Parvovirus B19 has a marked tropism for erythroid progenitor cells. This may lead to chronic anemia in predisposed individuals. The purpose of the study was to investigate the frequency of parvovirus B19 infections in patients with diagnosis of haematological disorders. In order to determine the diagnostic use of different markers of parvovirus B19 infection, serum specimens obtained from 79 patients with haematological disorders were tested for specific antibodies and viral DNA through the use of ELISA and PCR techniques. Evidence of parvovirus B19 infection was found in 23/79 (29.1%) patients by demonstrating viral DNA and/or specific IgM antibody. B19 infection was established in 3 of 11 patients with chronic myeloid leukemia, in 3 of 11 acute myeloid leukemia, in 2 of 11 patients with multiple myeloma, in 3 of 8 patients with Hodgkin's lymphoma, in 5 of 10 patients with non-Hodgkin's lymphoma, in 1 of 6 patients with myelodysplastic syndrome, in 4 of 11 patients with chronic lymphocytic leukemia, and in 2 of 11 patients with acute lymphocytic leukemia. In 4 of 23 positive patients, only parvovirus B19 DNA could be detected, while 7 patients were tested positive for both parvovirus B19 DNA and specific IgM. Nine patients were tested positive for both B19 DNA and specific IgG In the remaining 3 positive patients only specific IgM could be detected. Due to the discrepancies between DNA and IgM results, the diagnostic procedures should include a search for specific DNA by PCR methods if specific IgM has been found to be negative.