401 mandibular body fractures occurring during a 5-year period were analysed retrospectively. Out of these, 38 fractures (9.5%) were not consolidated by 50 days and made up the delayed healing group (DHG). A control group (CG) of another 38 fractures was constituted using the first mandibular body fracture consecutively following one in the DHG. The mean time until consolidation of the fractures was 116 days in the DHG and 35 days in the CG. The 2 groups were statistically analysed and mutually compared using a great number of variables including patient-, fracture site-, treatment- and end-result characteristics. It was concluded that a few days delay between trauma and treatment did not necessarily lead to a delayed healing. Uncooperative alcoholics with psycho-social handicaps, and general as well as local periodontitis, were found to be especially liable to consolidate their fractures at a slower rate than the average patient. The DHG more often required changes of unstable dental fixation, prolonged maxillo-mandibular fixation time and treatment for late infections at the fracture site. The patients in this group lost more teeth than those in the CG but above all required considerably extended therapeutic efforts. It is suggested that patients with the abovementioned characteristics should be given special attention and care.