Human parvovirus B19 (PV-B19) infection may lead to very serious clinical situations such as transient aplastic crisis in patients with hemolytic anemia, thrombocytopenia, neutropenia and transient arthritis accompanied with erythema infectiosum, especially in immunosuppressed patients. Early diagnosis of PV-B19 infection is of critical importance especially in immunosuppressed patients since the necessary precautions can be undertaken accordingly. In this study, PV-B19 IgM and IgG antibodies and viral DNA have been searched by enzyme immunoassay (ELISA) and real-time polymerase chain reaction (PCR), respectively, in 50 PV-B19 suspected immunosuppressed patients. Viral IgM, IgG and DNA positivities were detected in 7 (14%), 20 (40%) and 7 (14%) of the patients, respectively. During the first week three patients were found DNA and IgM positive but IgG negative, while four patients were found positive for the viral DNA, IgM and IgGs. The DNA copy numbers were high in all of the patients during the first week, with a gradual decrease during a seven-week follow-up period. IgM antibodies have disappeared in the sixth week in three of the patients and at the end of the seventh week in four of the patients. Although the IgG antibodies were negative in three patients in the first week, they became positive in the second week and the titers gradually increased during the following weeks. According to the results of this study, it can be concluded that, in high risk groups such as immunosuppressed patients, in addition to ELISA, real-time PCR method would be helpful for the early diagnosis of PV-B19 infections.