Secure coding practices are important for Microsoft .NET applications as adoption of web services increases. The paper outlines secure coding tenants specific to .NET applications and gives suggestions for the Visual Studio .NET environment. It focuses on five common ASP.NET security flaws: injection issues, authentication/authorization weaknesses, view state manipulation, cross-site scripting vulnerabilities, and insecure server configuration. Following secure coding practices can help developers build more robust and secure .NET applications.