Actinomycosis or mycetoma is an infectious process caused by a fungal or bacterial agent, giving a pseudotumoral appearance. The evolution is insidious; the bone location at the foot of the far more common; bone disease is a complication that increases the therapeutic management. We report the case of an adult male of 40 years, admitted to swelling of the midfoot, and in histological examination confirmed actinomycosis. Medically treated by antibiotherapy with a favorable outcome. The aim of this work is to recall this affection often unrecognized by rheumatologists so the therapeutic modalities.