We describe one female with acute polyarthritis and transitory rash. The arthritis of sudden onset, is localized in large and small joints and accompanied by significant stiffness, particularly noted in early morning. The symptoms only improvement a few with nonsteroidal anti-inflammatory drugs and the arthritis resolved within a few days. The diagnosis is based in the presence of anti-B19 IgM. The differential diagnosis of the acute polyarthritis is extensive, serological test should be made when we suspect the presence of a viral arthritis.