To determine if B19 infection persists in patients with chronic B19 arthropathy, acute B19 infection in adults was documented by IgM serology. Bone marrow aspirates were obtained 24-42 months after acute infection in 4 patients who developed chronic joint symptoms. DNA from bone marrow aspirates was amplified by polymerase chain reaction by using B19-specific DNA sequences in the viral capsid gene and probing with B19-specific oligonucleotidesin Southern analysis. B19-specific DNA sequences were detected in all 4 chronic arthropathy patients compared with 0 of 7 anti-B19 IgM−, IgG− and 0 of 6 anti-B19 IgM−, IgG+ normal bone marrow donors. Three patients with serologically proven acute B19 infection and acute but nonchronic joint symptoms had B19 DNA detected in bone marrow aspirates 2-18 months after infection. These findings suggest that B19 arthropathy is associated with persistence of either B19 virus or select B19 DNA sequences. © 1993 by The University of Chicago.