We describe the cases of two patients with clinical and radiological findings of the reflex sympathetic dystrophy syndrome (RSDS) in whom the history of a previous genito-urinary inflammation and high levels of ESR lead us to suspect a hidden reactive arthritis. However, instrumental examinations showed a characteristic picture of RSDS without evident signs of arthritis. In both patients we decided a treatment with quinolones because of detection of an ureaplasma urealyticum genito-urinary infection. This brought to complete remission of the joint symptoms in a few days. Our findings suggest that ureaplasma urealyticum can cause and sustain a RSDS picture, maybe with a reactive arthritis-like mechanism, and that an antibiogram-driven antimicrobial treatment can be rapidly effective against this disorder.