Oncogene expression in human neoplasia has been examined extensively in the past decade. More recently the advent of the polymerase chain reaction (PCR) has facilitated studies of oncogenes and other DNA structures. Those few studies which have so far searched for oncogene changes in oral cancer have utilized frozen specimens. We report here an adaptation of the PCR technique applicable to DNA extracted from archival specimens. Our data complement recent findings that Ha-ras mutations are infrequent in oral squamous cell carcinomas among white caucasoid populations.