BACKGROUND: Meningococcal infection is a multifaceted disease including acute polyarthritis. This presentation should be known by clinicians in order to prevent delay in treatment. We report what we believe to be the first case of an association of parvovirus B19 and meningococcal polyarthritis in a young adult. CASE PRESENTATION: A 19-year-old Caucasian woman presented to our hospital with fever, intense leg pain, and a transient rash. A physical examination showed asymmetric polyarthritis and no neurological abnormalities. A parvovirus B19 polymerase chain reaction performed using a blood sample and knee fluid aspirate came back positive, but serology was negative for immunoglobulin M and positive for immunoglobulin G. A blood culture was positive for serotype C meningococcus; a polymerase chain reaction performed for Neisseria meningitidis was positive in joint fluid but negative in blood samples (performed after antibiotic treatment had begun). Our patient was treated with ceftriaxone for 15 days, associated with analgesic therapy. Hydroxychloroquine treatment was introduced 5 months after the onset of polyarthritis because of persisting inflammatory arthralgia. CONCLUSIONS: To the best of our knowledge, this is the first case report of polyarthritis caused by concomitant meningococcal and parvovirus B19 infections. This unusual presentation of meningococcal disease may have resulted from the persistent parvovirus B19 infection. Our experience with this case illustrates the need for a systematic approach to the diagnosis of febrile acute polyarthritis. Only long-term follow-up will reveal if this infectious polyarthritis will evolve towards an autoimmune rheumatism.