Feline leukemia virus is a retrovirus of domestic cats that occurs throughout the world. Persistent infection in the animals and persistently infected cats are at risk for developing of fatal diseases such as: lymphoma, leukemia, haematopoietic malignancies and anemia. In this study as the first time in Iran the serologic prevalence of feline leukemia virus was determined with commercial ELISA method. Sampling was performed randomly from 103 domestic and stray cats. Positive serologic result was diagnosed in five cases (4.8%). All the positive cats belonged to domestic group. There wasn't any significant differences depend on sex or age, but most Positive cases were less than 3 years old. With respect to some difficulties in vaccination protocols against feline leukemia virus, detection of the infected animals and prevention of their contact with healthy cats is considered as best method in prevention of the disease.