Aim: To evaluate the efficacy of bioglass (BAG-S53P4) in the treatment of patients with chronic osteomyelitis and compare the results with calcium sulphate antibiotic beads in one medical centre.Methods: Retrospective analysis of 25 cases. Inclusion criteria: patients diagnosed clinically and radiographically of osteomyelitis and treated surgically (Group 1: cavitary bone defects treated with bioglass and Group 2: cavitary bone defects treated with calcium sulphate antibiotic beads) during the period of 2014 and 2015 in one medical centre.Results: Patients in group 1 (bioglass treatment): total of 12 patients (11 males and 1 female) with mean age: 50 years (30-86). Average length of hospital stay was 22 days and mean follow-up time: 23 months (16-33). Mean erythrocyte sedimentation rate (ESR) and mean c-reactive protein (CRP) before surgery: 55mm/hr and 54 mg/L, respectively. Mean ESR and mean CRP in last blood exam: 18 mm/hr and 8 mg/L, respectively. There were 2 postoperative complications: seroma formation and delayed wound healing. Only 1 patient had recurrence of infection.Patients in group 2 (calcium sulphate antibiotic beads treatment): total of 13 patients (9 males and 4 females) with mean age: 48 years (17-67). Average length of hospital stay was 21 days and mean follow-up time 22 months (16-29). Mean ESR and mean CRP before surgery: 51mm/hr and 41 mg/L, respectively. Mean ESR and mean CRP in last blood test: 15 mm/hr and 11 mg/L. 2 postoperative complications were registered: chronic expanding hematoma of the muscle flap donor site and seroma formation. 1 patient had recurrence of infection. Overall, there were no differences in recurrence of infection, p=0.740 and in complication rate, p=0.672. 11 (91,7%) patients in group 1 and 12 (92,3%) patients in group 2 showed no signs of recurrence of infection both clinically and radiologically at final follow-up.The most frequent cause of osteomyelitis in group 1 was post traumatic while a postsurgical aetiology was more frequent in group 2. The distal tibia was the most common location. The most frequent pathogen isolated in both groups was methicillin sensible staphylococcus aureus.Conclusions: An advance in treatment of patients with cavitary bone defects in chronic osteomyelitis is the use of synthetic bone substitutes although current evidence is low. In this study, we demonstrate how bioglass without local antibiotics and calcium sulphate antibiotic beads are both equally effective treatment options. Overall, there were no differences between groups in mean hospital stay, complication rates and recurrence of infection.