Purpose: The aim of this study was to evaluate the shear bond strength of two adhesive systems when applied on dentin surfaces with different degrees of wetness. Materials and Methods: Two-hundred ten dentin specimens were used. After conditioning with 35% phosphoric acid gel and washing, seven methods of drying dentin were used: 30 s air spray (groups 1 and 2), 5 s air spray (groups 3 and 4), dry cotton pellets (groups 7 and 8), wet cotton pellets (groups 9 and 10), microbrush (groups 11 and 12), absorbent paper (groups 13 and 14). The last group was not dried; the dentin surfaces were left overwet (groups 5 and 6). Prime & Bond 2.1 adhesive was applied on the odd- numbered groups and Scotchbond Multi Purpose on the even-numbered groups. Z100 composite cylinders were bonded to the adhesive and the specimens were subjected to a shear bond test. Results: The Least-Squares Means test was used to compare the following results, where different letters indicate significantly different mean values: Group 9 (G9) = 23.2 MPa (a), G3 = 21.3 MPa (ab), G2 = 19.5 MPa (be], G10 = 18.6 MPa (be!, G14 = 16.3 MPa (cd), G8 = 16.1 MPa (cd), G4 = 14.6 MPa (de), G13 = 14.0 MPa (de), Gil = 13.9 MPa (de), G7 = 13.5 MPa (de), G12 = 12.1 MPa (e), Gl = 8.2 MPa (f), G5 = 2.7 MPa (g), G6 = 2.4MPa (g). Conclusion: The adhesion values were affected both by the degree of dentin wetness and by the adhesive systems.