The ASME B31.3 code can be used for simple and low-cycle fatigue. However, more complex and high-cycle fatigue is better analyzed using fatigue curves from the pressure vessel codes. CAESAR II is a powerful tool that can be used for all types of piping fatigue analyses. This session will discuss the theoretical and code requirements of fatigue analysis for ASME B31.3 piping. The features of CAESAR II will be presented to allow the attendees to efficiently produce fatigue analysis.