The amount of occlusal surface area covered when fissure sealant is applied to a tooth has not been previously reported. This study measured the occlusal surface area and sealant surface area using a computer-driven profilometric system. Twenty-two recently erupted, caries-free premolars were used. The mean occlusal area for all premolars was 34.34 mm² ±4.42 mm². The mean surface area of applied sealant for all teeth was 8.06 mm²± 1.67 mm², and the mean percentage of occlusal surface area covered by sealant was 23.9 7% ±5.02%. The occlusal surface area of mandibular first premolars was signnificantly smaller than that of the other premolar groups. However, this difference was not reflected in the area of sealant applied to premolars or in the percentage of occlusal surface covered by sealant. Mandibular first premolars required the same amount of coverage as the other tooth groups.