The results of nonoperative treatment of metatarsophalangeal (MP) joint synovitis in 13 patients without known rheumatologic conditions (15 joints) were reviewed. Average duration of forefoot pain was 4 +/- 3 months (range 0.5-12 months), except for one patient who had pain for 30 months. The second MP joint was involved in nine cases (60%), and the third was involved in six cases (40%). Examination revealed tenderness and palpable fullness of the MP joint in all cases; painful dorsal drawer sign was present in 10 cases (67%), adjacent interdigital tenderness in six cases (40%), and hammertoe deformity in eight cases (53%). Treatment included intra-articular corticosteroid injection and rocker-sole show modification to limit MP joint dorsiflexion. At follow-up evaluation (18 +/- 9 months, range 4-26 months), the involved MP joint was asymptomatic in nine joints (60%), improved or almost asymptomatic in five joints (33%), and operated in one (7%) joint. Two of seven (29%) joints not initially associated with hammertoe developed a mild hammertoe deformity from time of diagnosis to follow-up. In conclusion, nonoperative treatment can be effective for MP joint synovitis, and the incidence of progressive hammertoe deformity in successfully treated cases is low.