The purpose of this in vitro study was to investigate the marginal and internal fit of Cerec-2 inlays before and after adhesion. The test showed: 1. Before luting, the axial marginal space was 67 +/- 18 microns, cervical marginal space was 84 +/- 22 microns and the mean occlusal marginal space was 58 microns. 2. After luting, the thickness of the luting composite was 118 +/- 37 microns at axial margin, and 123 +/- 17 microns at cervical margin, the mean occlusal margin space was 80 microns. This study demonstrated the marginal adaptation of Cerec-2 inlays satisfied the clinical demand, especially at occlusal margin.