Leptospirosis is a cosmopolitan natural-focal disease representing a serious problem for the majority of the countries in the world including the Russian Federation because this infection causes a serious economic and social damage. Modern laboratory diagnostics of leptospiroses is based on a complex of bacteriological, immunological and molecularbiological methods used in various combinations depending on the problems and possibilities of the laboratories. At all variety, many methods are not applied in practice and the gold standard still remains the routine serological method. Disease diagnostics is based on a set of epidemiological, epizootological, clinical and pathoanatomical data with obligatory laboratory verification of the diagnosis. However often laboratory verification is retrospective or in general absent. For achievement of the best results in leptospirosis diagnostics, it is necessary to improve the available laboratory methods and to use it in practice. Especial attention should be given to introduction of new molecular technologies that simplify laboratory diagnostics and expand its possibilities.