Inducible nitric oxide synthase (iNOS) is a cytoplasmic enzyme which plays a crucial role in the pathogenesis of oral carcinomas and sarcomas. This study analyzed the immunohistochemical expression of iNOS in 20 carcinomas and 20 sarcomas and correlated the findings with lymph node metastasis. iNOS positivity was seen in 19 carcinomas, of which 15 showed lymph node metastasis. Hard tissue sarcomas showed higher iNOS positivity compared to soft tissue sarcomas. iNOS proved to be a reliable marker for lymph node metastasis and angiogenesis in carcinomas.