Primary meningococcal arthritis (PMA) is a rare infectious disease that occurs in as little as 1% of meningococcal infections.1 PMA is arthritis without meningitis, fever, rash, and hemodynamic instability.2 It is usually preceded by an upper respiratory infection in 50–55% of presentations, and patients may appear nontoxic, afebrile, and polyarthralgic. Despite definition they may have a rash.3–12 Although PMA is rare, one would expect immunocompromised patients to be more susceptible to develop this disease. However, in areas of high prevalence of human immunodeficiency virus (HIV) infection, just outside the meningococcal belt in the Gabonese Republic of Africa, HIV-infected patients were not found to be at higher risk for Neisseria meningococcal disease.13 Furthermore, a small study by Skeete et al14 showed patients with a compromised immune system were not more likely to have normal peripheral white blood cell (WBC) count during septic arthritis. With such a variable presentation of septic arthritis, it can be extremely difficult to diagnose a septic joint without a high clinical suspicion. Numerous studies indicate that previous joint disease and low socioeconomic class do appear to be risk factors for developing septic arthritis, although N. meningococcal disease was not included.12 There are no well-studied or validated clinical criteria that can be used when attempting to diagnose PMA. While the literature varies most orthopedists will use a WBC count of 5.0–10.0 × 103 cells/μL or greater and no synovial fluid crystals before they will consider the diagnosis of a septic joint. Septic arthritis has been diagnosed by intra-articular cultures in 7–10% of cases with a joint fluid aspirate WBC count of less than 10.0 × 103 cells/μL, but none of these studies included N. meningococcal disease. The literature also supports the finding that traditional septic arthritis joints have an elevation in at least 1, if not several, of the following: peripheral WBC count, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), or joint aspirate WBC.15–17 Furthermore, when looking at the case studies published, we found that all but 4 cases of PMA had purulent aspirate, with these 4 cases having synovial WBC count ranging from 17–163,000 cells/μL.6–8,18 We will present a unique case of PMA with non-purulent joint aspirate with normal peripheral WBC and joint fluid WBC count of 8.7 × 103 cells/μL in an HIV-positive patient with a CD4 count reflecting a functional immune system.