This chapter presents an overview of methods for studying biodegradation. It discusses the importance of choosing the well characterized, relevant sample and right biotic environment as well as preparing relevant controls. Respirometry is one of the most sensitive methods for calculating the degradation of polymers. For both environmental and biomedical use we need degradable polymer with non-toxic degradation products. According to American Society for Testing and Materials (ASTM) standard a petri-dish test of a polymer's biodegradability is an appropriate initial routine test. The properties of the sample are dependent on every detail in the sample preparation and history. For measurements as tensile strength the standard shape, for polymer film the parallel-sided strip is recommended in the ASTM standard. Another means of obtaining quick biodegradation is by using enzymes but, this is not always the most effective way and demands more careful performance than using the microorganisms themselves. Microorganisms can only be activated with a favorable environment for their growth.