An osteoplastic frontal sinus flap with flat obliteration is the "gold" standard for the management of chronic frontal sinus inflammatory disease caused by obstruction of the nasofrontal duct. Frontal sinusotomy, with an osteoplastic technique, call for osteotomies, guided by a template obtained from a Caldwell radiographic view taken at a distance of 6 feet. The reliability of the template depends on the position of the patient, distance at which the radiograph is taken, penetration of the x-rays, and other technical aspects. Therefore the template is a potential source of error. We present the use of a computer-assisted frontal sinusotomy as a method to corroborate the shape and margins of the frontal sinus in six patients undergoing obliterative frontal sinus surgery. In our hands, this technique has proved more reliable than the radiographic template to corroborate the positioning of the osteotomies.