diff --git a/crates/pixi/tests/integration_rust/add_tests.rs b/crates/pixi/tests/integration_rust/add_tests.rs
index 64599a9b8f..bacd87af26 100644
--- a/crates/pixi/tests/integration_rust/add_tests.rs
+++ b/crates/pixi/tests/integration_rust/add_tests.rs
@@ -1205,3 +1205,63 @@ preview = ['pixi-build']
         insta::assert_snapshot!(workspace.workspace.provenance.read().unwrap().into_inner());
     });
 }
+/// Test the `pixi add --pypi --index` functionality
+#[cfg(unix)]
+#[tokio::test(flavor = "multi_thread", worker_threads = 1)]
+async fn add_pypi_with_index() {
+    use crate::common::pypi_index::{Database as PyPIDatabase, PyPIPackage};
+    setup_tracing();
+    // Create local PyPI index with test package
+    let pypi_index = PyPIDatabase::new()
+        .with(PyPIPackage::new("requests", "2.32.0"))
+        .into_simple_index()
+        .unwrap();
+    // Create local conda channel with Python
+    let mut package_db = MockRepoData::default();
+    package_db.add_package(
+        Package::build("python", "3.12.0")
+            .with_subdir(Platform::current())
+            .finish(),
+    );
+    let channel = package_db.into_channel().await.unwrap();
+    let pixi = PixiControl::new().unwrap();
+    pixi.init()
+        .without_channels()
+        .with_local_channel(channel.url().to_file_path().unwrap())
+        .await
+        .unwrap();
+    // Add python
+    pixi.add("python==3.12.0")
+        .set_type(DependencyType::CondaDependency(SpecType::Run))
+        .await
+        .unwrap();
+    // Add a pypi package with custom index
+    let custom_index = pypi_index.index_url().to_string();
+    pixi.add("requests")
+        .set_type(DependencyType::PypiDependency)
+        .with_index(custom_index.clone())
+        .await
+        .unwrap();
+    // Read project and check if index is set
+    let project = Workspace::from_path(pixi.manifest_path().as_path()).unwrap();
+    let pypi_deps: Vec<_> = project
+        .default_environment()
+        .pypi_dependencies(None)
+        .into_specs()
+        .collect();
+    // Find the requests package
+    let (_name, spec) = pypi_deps
+        .iter()
+        .find(|(name, _)| *name == PypiPackageName::from_str("requests").unwrap())
+        .expect("requests package should be in dependencies");
+    // Verify the index is set correctly
+    if let PixiPypiSpec::Version { index, .. } = spec {
+        assert_eq!(
+            index.as_ref().map(|u| u.as_str()),
+            Some(custom_index.as_str()),
+            "Index URL should match the provided custom index"
+        );
+    } else {
+        panic!("Expected PixiPypiSpec::Version variant");
+    }
+}
diff --git a/crates/pixi/tests/integration_rust/common/builders.rs b/crates/pixi/tests/integration_rust/common/builders.rs
index ad737970bf..d9aa31722d 100644
--- a/crates/pixi/tests/integration_rust/common/builders.rs
+++ b/crates/pixi/tests/integration_rust/common/builders.rs
@@ -244,6 +244,11 @@ impl AddBuilder {
         self
     }
 
+    pub fn with_index(mut self, index: String) -> Self {
+        self.args.index = Some(index);
+        self
+    }
+
     /// Deprecated: Use .with_frozen(true).with_install(false) instead
     pub fn with_no_lockfile_update(mut self, no_lockfile_update: bool) -> Self {
         if no_lockfile_update {
diff --git a/crates/pixi/tests/integration_rust/common/mod.rs b/crates/pixi/tests/integration_rust/common/mod.rs
index 9bfd856367..2289436845 100644
--- a/crates/pixi/tests/integration_rust/common/mod.rs
+++ b/crates/pixi/tests/integration_rust/common/mod.rs
@@ -454,6 +454,7 @@ impl PixiControl {
                 },
                 config: Default::default(),
                 editable: false,
+                index: None,
             },
         }
     }
diff --git a/crates/pixi_cli/src/add.rs b/crates/pixi_cli/src/add.rs
index e3daa084f4..48b8da976d 100644
--- a/crates/pixi_cli/src/add.rs
+++ b/crates/pixi_cli/src/add.rs
@@ -1,10 +1,13 @@
 use clap::Parser;
+use miette::{IntoDiagnostic, WrapErr};
 use pixi_api::{
     WorkspaceContext,
     workspace::{DependencyOptions, GitOptions},
 };
 use pixi_config::ConfigCli;
 use pixi_core::{DependencyType, WorkspaceLocator};
+use pixi_pypi_spec::PixiPypiSpec;
+use url::Url;
 
 use crate::{
     cli_config::{DependencyConfig, LockFileUpdateConfig, NoInstallConfig, WorkspaceConfig},
@@ -92,6 +95,10 @@ pub struct Args {
     /// Whether the pypi requirement should be editable
     #[arg(long, requires = "pypi")]
     pub editable: bool,
+
+    /// The URL of the PyPI index to use for this dependency
+    #[arg(long, requires = "pypi")]
+    pub index: Option<String>,
 }
 
 impl TryFrom<&Args> for DependencyOptions {
@@ -158,6 +165,21 @@ pub async fn execute(args: Args) -> miette::Result<()> {
                 .await?
         }
         DependencyType::PypiDependency => {
+            // Parse the index URL if provided
+            let index_url = args
+                .index
+                .as_ref()
+                .map(|url_str| Url::parse(url_str))
+                .transpose()
+                .into_diagnostic()
+                .wrap_err("Failed to parse index URL")?;
+
+            // Create PixiPypiSpec if index is provided
+            let pixi_spec = index_url.map(|url| PixiPypiSpec::Version {
+                version: pixi_pypi_spec::VersionOrStar::Star,
+                extras: Vec::new(),
+                index: Some(url),
+            });
             let pypi_deps = match args
                 .dependency_config
                 .vcs_pep508_requirements(&workspace)
@@ -165,13 +187,13 @@ pub async fn execute(args: Args) -> miette::Result<()> {
             {
                 Some(vcs_reqs) => vcs_reqs
                     .into_iter()
-                    .map(|(name, req)| (name, (req, None, None)))
+                    .map(|(name, req)| (name, (req, pixi_spec.clone(), None)))
                     .collect(),
                 None => args
                     .dependency_config
                     .pypi_deps(&workspace)?
                     .into_iter()
-                    .map(|(name, req)| (name, (req, None, None)))
+                    .map(|(name, req)| (name, (req, pixi_spec.clone(), None)))
                     .collect(),
             };
 
diff --git a/docs/reference/cli/pixi/add.md b/docs/reference/cli/pixi/add.md
index 3ad53ee7a2..837f6b5f82 100644
--- a/docs/reference/cli/pixi/add.md
+++ b/docs/reference/cli/pixi/add.md
@@ -30,6 +30,8 @@ pixi add [OPTIONS] <SPEC>...
 <br>**default**: `default`
 - <a id="arg---editable" href="#arg---editable">`--editable`</a>
 :  Whether the pypi requirement should be editable
+- <a id="arg---index" href="#arg---index">`--index <INDEX>`</a>
+:  The URL of the PyPI index to use for this dependency
 
 ## Config Options
 - <a id="arg---auth-file" href="#arg---auth-file">`--auth-file <AUTH_FILE>`</a>