This article provides a general overview of behaviour-driven development (BDD) in a .NET context. I presents some .NET tools for BDD (SpecFlow) and UI testing (White) and proceeds with a working example giving hands on BDD in .NET. SpecFlow is an open source tool aims to provide a pragmatic and frictionless approach to Acceptance Test Driven Development and Behavior Driven Development for .NET projects. White is an open source framework for automating rich client applications based on Win32, WinForms, WPF, Silverlight and SWT (Java) platforms. It is .NET based and does not require the use of any proprietary scripting languages. Tests automation programs using White can be written with whatever .NET language, IDE and tools.