This book details microbiological analysis of aviation fuel and fuel handling systems at CITA Petroleum Limited, Nigeria. Bacteria and fungi were isolated from the storage facilities sampled. This work has laid a solid foundation of the microbial data base and diversity of this unique environment and their possible effect on stored fuels in the tropics. Standards based on climatologic differences are suggested to be more realistic. The use of standard microbiological methods in identifying and quantifying microbes in fuels may be considered more reliable than species-specific methods which are in current use.