Controlled substances are often encountered by forensic practitioners and law enforcement officials in the field. In this chapter, drug evidence collection and handling procedures are introduced. Proper scene assessment and methods of documentation for drug evidence are also discussed. Special considerations, such as proper collection tools, safety precautions and proper protective equipment, are addressed. Sampling plans, as recommended by professional standards in the field of controlled substance analysis, are discussed. Proper evidence handling and collection at clandestine laboratories, including necessary safety precautions, assessing the presence of chemical hazards and collection of precursor or finished products, are also discussed.