diff --git a/src/api/SIGCM2.Domain/Exceptions/RubroConProductosActivosException.cs b/src/api/SIGCM2.Domain/Exceptions/RubroConProductosActivosException.cs
new file mode 100644
index 0000000..e55fb34
--- /dev/null
+++ b/src/api/SIGCM2.Domain/Exceptions/RubroConProductosActivosException.cs
@@ -0,0 +1,17 @@
+namespace SIGCM2.Domain.Exceptions;
+
+/// <summary>
+/// Thrown when attempting to soft-delete a Rubro that still has active Products referencing it via RubroId. → HTTP 409
+/// </summary>
+public sealed class RubroConProductosActivosException : DomainException
+{
+    public int RubroId { get; }
+    public int ProductosActivosCount { get; }
+
+    public RubroConProductosActivosException(int rubroId, int productosActivosCount)
+        : base($"No se puede desactivar el rubro {rubroId}: tiene {productosActivosCount} producto(s) activo(s) referenciándolo.")
+    {
+        RubroId = rubroId;
+        ProductosActivosCount = productosActivosCount;
+    }
+}
diff --git a/tests/SIGCM2.Application.Tests/Domain/Rubros/RubroConProductosActivosExceptionTests.cs b/tests/SIGCM2.Application.Tests/Domain/Rubros/RubroConProductosActivosExceptionTests.cs
new file mode 100644
index 0000000..b8c433a
--- /dev/null
+++ b/tests/SIGCM2.Application.Tests/Domain/Rubros/RubroConProductosActivosExceptionTests.cs
@@ -0,0 +1,27 @@
+using FluentAssertions;
+using SIGCM2.Domain.Exceptions;
+
+namespace SIGCM2.Application.Tests.Domain.Rubros;
+
+public class RubroConProductosActivosExceptionTests
+{
+    [Fact]
+    public void Constructor_SetsPropertiesAndMessage()
+    {
+        var ex = new RubroConProductosActivosException(rubroId: 7, productosActivosCount: 3);
+
+        ex.RubroId.Should().Be(7);
+        ex.ProductosActivosCount.Should().Be(3);
+        ex.Message.Should().Contain("7");
+        ex.Message.Should().Contain("3");
+        ex.Message.Should().Contain("producto");
+    }
+
+    [Fact]
+    public void Constructor_InheritsFromDomainException()
+    {
+        var ex = new RubroConProductosActivosException(1, 2);
+
+        ex.Should().BeAssignableTo<DomainException>();
+    }
+}