This article discusses some of the pitfalls and disadvantages of Mohs micrographic surgery for the excision of skin cancer. These include (1) frozen section quality; (2) interpretation of frozen sections; (3) holes in fragmented tissue margins; (4) tissue orientation problems; (5) excessively narrow or wide margins; (6) transection of the tumor itself; (7) problems with multifocal tumor; and (8) the tedious, time-consuming nature of the procedure. Despite these problems, the importance of the procedure in the treatment of cutaneous neoplasms should not be underestimated.