Frozen section is a very helpful ancillary procedure to the surgeon in guiding him in his decision intraoperatively. Indications include: to establish the presence & nature of lesion, determine adequacy of surgical margins and to establish whether the tissue obtained contained diagnosable material. The accuracy of frozen section varied depending on the author and type of tissues. In this retrospective study (1994-2005), we reviewed and evaluated the accuracy of frozen section diagnosis in 114 lesions. The most common site sent for frozen section diagnosis was the mediastinum, followed by the lung and breast. There were 47 percent true positive, 54 percent true negative and 2.7 percent false negative. There were no cases of false positive frozen section diagnosis. In our study, frozen section is very accurate in diagnosing mediastinal, pulmonary and breast lesions. Because it is very difficult to diagnose lymphoma on frozen section, there were 3 cases of false negative diagnosis. This is also true in diagnosing breast tumor. A single case of frozen section of a breast tissue had a deferred diagnosis. Frozen section has some limitations; so, recommend good communication between the surgeon and pathologist to avoid misdiagnosis.