목적: Frozen section (FS) is routinely used to identify microscopic spread of disease beyond tumor edge that is clinically occult. However almost all studies suggest that use of FS does not impact the survival. Besides there is hardly any publications on prevalence of such Microscopic spread. We evaluated the impact of microscopic spread on the margin status. Our primary aim was to study the cost benefit analysis of FS in the assessment of margins. 방법:This is a retrospective study of 1311 consecutive patients, operated for oral cavity squamous cell carcinoma from January 2012 to October 2013. FS was performed in 1237 (94.3%) patients. The gross and microscopic margin status of each patient was extracted from electronic medical records. The cost estimates were performed to calculate the expenditure on FS and also on adjuvant treatment resulting from inadequate margins. Activity based cost analysis was performed to estimate indirect institution associated expenses for FS. 결과:Microscopic spread changed the gross margin status in 5.2% patients. FS was beneficial in 1 out of 43 patients (2.3%) to achieve tumor free margin and it affected the adjuvant treatment plan in 1 out of 137(0.7%) patients. The total cost of entire cohort was USD 227814.2. Total costs for adjuvant CT-RT and adjuvant RT in our centre were USD 3750 and USD 3016.7 per patient. FS saved USD 18666.7 as additional cost of adjuvant treatment in total 9 patients in entire cohort. Thus additional expenditure due to FS is USD 209147.5. The cost benefit ratio of FS was 121. Gross examination alone could have identified majority of the inadequate margins. 결론:Use of Frozen section for the assessment of surgical margin bears poor cost benefit ratio. Meticulous gross examination of the entire surgical specimen is pivotal in identifying majority of inadequate margins.