Mohs' surgery of periocular basal cell carcinoma (BCC) ensures a high cure rate with maximal preservation of normal tissue. The formalin-fixed paraffin-embedded tissue technique allows Mohs' surgery to be performed using routine pathology facilities and permits the efficient use of operating room personnel and theatre time. The inevitable delay between excision and closure may potentially result in a poor functional and cosmetic outcome, particularly around the eye. We prospectively studied all patients with periocular BCC treated with this technique at our unit between 1985 and 1996. One hundred and twenty-three periocular BCCs in 120 patients were treated. Microscopic clearance was achieved in all cases. Closure was performed on average 5 days after the initial excisional stage. Closing procedures included direct closure, flaps and grafts. Significant complications affecting outcome were noted in only two patients. Eighty-eight per cent of patients assessed had a functional and cosmetic result regarded as excellent, good or adequate. Mohs' surgery of periocular BCC using formalin-fixed paraffin-embedded tissue and delayed closure results in a satisfactory functional and cosmetic outcome and offers a viable alternative to the frozen section fresh tissue technique.