Osteomyelitis is an infectious process in bone that occasionally leads to bone destruction. Traditionally the surgical treatment procedure is performed in combination with systemic and local antibiotics as a two-stage procedure that uses autograft or allograft bone for filling of the cavitary defect. Bioactive glass (BAG-S53P4) is a bone substitute with proven antibacterial and bone bonding properties. One hundred and sixteen patients who had verified chronic osteomyelitis was treated using BAG-S53P4 as part of the treatment. Most of the patients had previously undergone numerous procedures sometimes for decades. A register of patient data obtained from 11 centers from Finland Italy the Netherlands Germany Azerbaijan and Poland was set-up and continuously maintained at Helsinki University Central Hospital. The location of the osteomyelitis was mainly in the tibia followed by the femur and then the calcaneus. The median age of the patients was 48 years (15–87). The patients were either treated according to a one-stage procedure without local antibiotics (85 %) or by a two-stage procedure using antibiotic beads in the first procedure (15 %). The minimum follow-up was 1 year (12–95 months median 31). The cure rate was 104/116 the total success rate 90 % and most of the patients showed a rapid recovery. The study shows that (BAG-S53P4) can be used in a one-stage procedure in treatment of osteomyelitis with excellent results.