Introduction Gonococcal arthritis is a characteristic of disseminated gonococcal infection (DGI). DGI arthritis is one of the most serious orthopedic emergencies because it can result in rapidly progressive joint damage, but it is often difficult to diagnose. Delayed treatment can result in the development of osteomyelitis in the adjacent bone, similar to other types of bacterial arthritis. Method We report a case of gonococcal osteomyelitis associated with DGI that was initially treated as rheumatoid arthritis. The diagnosis was confirmed by DNA testing of synovium collected during arthroscopic debridement. Results Seven years after the initial consultation, there was no acute-phase reactant, the arthritic changes had improved over time and the range of motion had increased. DGI may be difficult to confirm, but it is one of the most important entities that should be differentiated in the treatment of arthritis. Conclusion Clinicians need to keep in mind that blood and synovial fluid cultures often do not lead to a definitive diagnosis.