The aim of this study was to isolate Cryptococcus neoformans from pigeon droppings and eucalyptus debris which are known as the natural sources for this yeast and to determine the varieties and serotypes of these natural strains as of well as of the clinical strains isolated in cryptococcosis patients in Izmir, Turkey. In 90 pigeon dropping samples collected from Izmir and its environment eight (%8.8) C. neoformans strains were isolated using plate method and all of them were found as var. neoformans by canavanineglycine- bromthymol agar method and five of these were of serotype D (%62.5) while three were of serotype A (%37.5) by Cryptocheck slide aglutination method. From the eucalyptus debris samples no strain could be isolated. All of the five clinical strains isolated in cryptococcosis patients were determined as C. neoformans var. neoformans and serotype A using the same methods, respectively. It is concluded that, although for the first time it is determined that the natural C. neoformans strains are of serotypes A and D and clinical strains are of serotype A, multicenter studies are required on the subject.