diff --git a/src/domain/handler.rs b/src/domain/handler.rs
index 1af5ff0..3dd676b 100644
--- a/src/domain/handler.rs
+++ b/src/domain/handler.rs
@@ -4,16 +4,19 @@ use crate::infra::configuration::Configuration;
 use async_trait::async_trait;
 use futures_util::StreamExt;
 use futures_util::TryStreamExt;
-pub use lldap_model::*;
 use log::*;
 use sea_query::{Expr, Order, Query, SimpleExpr, SqliteQueryBuilder};
 use sqlx::Row;
+use std::collections::HashSet;
+
+pub use lldap_model::*;
 
 #[async_trait]
 pub trait BackendHandler: Clone + Send {
     async fn bind(&self, request: BindRequest) -> Result<()>;
     async fn list_users(&self, request: ListUsersRequest) -> Result<Vec<User>>;
     async fn list_groups(&self) -> Result<Vec<Group>>;
+    async fn get_user_groups(&self, user: String) -> Result<HashSet<String>>;
 }
 
 #[derive(Debug, Clone)]
@@ -155,6 +158,33 @@ impl BackendHandler for SqlBackendHandler {
 
         Ok(groups)
     }
+
+    async fn get_user_groups(&self, user: String) -> Result<HashSet<String>> {
+        let query: String = Query::select()
+            .column(Groups::DisplayName)
+            .from(Groups::Table)
+            .inner_join(
+                Memberships::Table,
+                Expr::tbl(Groups::Table, Groups::GroupId)
+                    .equals(Memberships::Table, Memberships::GroupId),
+            )
+            .and_where(Expr::col(Memberships::UserId).eq(user))
+            .to_string(SqliteQueryBuilder);
+
+        sqlx::query(&query)
+            // Extract the group id from the row.
+            .map(|row: DbRow| row.get::<String, _>("display_name"))
+            .fetch(&self.sql_pool)
+            // Collect the vector of rows, each potentially an error.
+            .collect::<Vec<sqlx::Result<String>>>()
+            .await
+            .into_iter()
+            // Transform it into a single result (the first error if any), and group the group_ids
+            // into a HashSet.
+            .collect::<sqlx::Result<HashSet<_>>>()
+            // Map the sqlx::Error into a domain::Error.
+            .map_err(Error::DatabaseError)
+    }
 }
 
 #[cfg(test)]
@@ -168,6 +198,7 @@ mockall::mock! {
         async fn bind(&self, request: BindRequest) -> Result<()>;
         async fn list_users(&self, request: ListUsersRequest) -> Result<Vec<User>>;
         async fn list_groups(&self) -> Result<Vec<Group>>;
+        async fn get_user_groups(&self, user: String) -> Result<HashSet<String>>;
     }
 }
 
@@ -369,4 +400,39 @@ mod tests {
             ]
         );
     }
+
+    #[tokio::test]
+    async fn test_get_user_groups() {
+        let sql_pool = get_initialized_db().await;
+        insert_user(&sql_pool, "bob", "bob00").await;
+        insert_user(&sql_pool, "patrick", "pass").await;
+        insert_user(&sql_pool, "John", "Pa33w0rd!").await;
+        insert_group(&sql_pool, 1, "Group1").await;
+        insert_group(&sql_pool, 2, "Group2").await;
+        insert_membership(&sql_pool, 1, "bob").await;
+        insert_membership(&sql_pool, 1, "patrick").await;
+        insert_membership(&sql_pool, 2, "patrick").await;
+        let config = Configuration::default();
+        let handler = SqlBackendHandler::new(config, sql_pool);
+        let mut bob_groups = HashSet::new();
+        bob_groups.insert("Group1".to_string());
+        let mut patrick_groups = HashSet::new();
+        patrick_groups.insert("Group1".to_string());
+        patrick_groups.insert("Group2".to_string());
+        assert_eq!(
+            handler.get_user_groups("bob".to_string()).await.unwrap(),
+            bob_groups
+        );
+        assert_eq!(
+            handler
+                .get_user_groups("patrick".to_string())
+                .await
+                .unwrap(),
+            patrick_groups
+        );
+        assert_eq!(
+            handler.get_user_groups("John".to_string()).await.unwrap(),
+            HashSet::new()
+        );
+    }
 }
diff --git a/src/domain/sql_tables.rs b/src/domain/sql_tables.rs
index ed53c70..cc74834 100644
--- a/src/domain/sql_tables.rs
+++ b/src/domain/sql_tables.rs
@@ -2,6 +2,7 @@ use sea_query::*;
 
 pub type Pool = sqlx::sqlite::SqlitePool;
 pub type PoolOptions = sqlx::sqlite::SqlitePoolOptions;
+pub type DbRow = sqlx::sqlite::SqliteRow;
 
 #[derive(Iden)]
 pub enum Users {