Of 52 fractures of the mandible treated over a 2-year period, sixteen involved the insertion of an osteosynthesis plate. The average period between the injury and application of the mandibular plate was 3.5 days (range: 8 hours to 14 days). Reasons for the delays in treatment are given, but it was observed that in spite of sometimes long periods before therapy the overall results could be considered as satisfactory, since poor results were reported in only 3 patients and in two of these there were particular circumstances. These findings suggest that the classical limit of the 8th hour is perhaps not the limit beyond which a mandibular osteosynthesis is valid, although delayed operation is only possible in certain well defined cases.