The aim of this study was to perform a preliminary clinical assessment of efficacy and safety of a biodegradable gentamicin-loaded monoolein gel. An open single dose, one treatment study including 19 patients with chronic osteomyelitis caused by a microorganism sensitive to gentamicin was conducted. After surgical curettage of the infected bone, the dead space was filled in with the gentamicin-loaded monoolein gel. To prevent post-operative septicaemia, a systemic antibiotherapy was prescribed for 3 days following the operation. Clinical,biological and radiological follow-up was performed to assess the efficacy and the safety of the treatment. After a follow-up period ranging from 2 to 12 months, all 19 patients included in the study felt well. Eighteen patients recovered from chronic osteomyelitis without adverse events. The wound of one patient whose bone was exposed did not scar over after 10 months. However, it was no longer infected In conclusion, gentamicin-loaded monoolein gel was efficacious in treating chronic osteomyelitis without side-effects.