The records of 130 consecutive patients undergoing marginal or segmental mandibulectomy for squamous cell carcinoma of the oral cavity or oropharynx were reviewed. An attempt was made to correlate incidence of recurrence with characteristics of the primary tumor and extent of mandibulectomy. The local recurrence rate was 19% following marginal mandibulectomy and 6% following segmental mandibulectomy. The incidence of local recurrence was independent of the size of the primary tumor or the extent of lymph node metastases. Neither mandibular invasion by tumor nor the addition of radiotherapy influenced local recurrence. Ten of 15 patients recurring locally after marginal mandibulectomy were salvaged by further surgery. This study suggests that local control following marginal mandibulectomy is comparable to that following segmental mandibulectomy regardless of the size of the tumor. Segmental mandibulectomy should be reserved for those tumors invading deeply into the mandible or wrapping around it.