Abstract: Targeted disruption of the centrin gene leads to attenuation of growth in the Leishmania. Preferred embodiments of the invention provide attenuated strains of Leishmania useful for the preparation of immunogenic preparations including vaccines against a disease caused by infection with a virulent Leishmania strain and as tools for the generation of immunological and diagnostic reagents. Other preferred embodiments provide related immunogenic compositions, methods of generating an immune response, methods for producing a vaccine, and methods of forming attenuated strains of Leishmania.