A comprehensive review of surgical margin in oral squamous cell carcinoma highlighting the significance of tumor-free surgical margins Mamata Kamat, Bhagawan Das Rai, Rudrayya S Puranik, Uma Vasant Datar Journal of Cancer Research and Therapeutics 2019 15(3):449-454 Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity, and surgery is the most accepted line of treatment. The surgical margins (SMs) or resection margins are boundaries of resection specimen excised by the surgeon. The status of these resected SMs is an important and valuable tool to predict the treatment outcome. It is necessary to attain optimal SM to avoid local recurrence and improve overall survival. However, the controversies exist regarding the concept of optimal SM. There are various factors that influence the assessment of the SMs. In addition, apart from routine histopathology, the molecular assessment of resected margins has recently gained value which has a promising role for margin surveillance. Furthermore, the histological and molecular appraisal of tumor-free margins is also necessary to standardize the treatment modalities. Hence, this review aims to summarize the above issues that influence the evaluation of SMs of OSCC along with recent updates. Furthermore, an attempt has been made to give an overview about future possible approaches for the tumor-free margins. An electronic search was performed for items related to the evaluation of SMs in OSCC, and the obtained articles were critically assessed and the relevant information was extracted and summarized.