The aim of this study was to evaluate, in vitro, the early tensile bond strength values of three dentin bonding agents (Scotchbond, Tenure and Gluma) to dentin. Fifteen non-carious, extracted, human third molars were used in this study. The bond strengths were calculated in an Instron test machine and expressed in MN/m2. The results were evaluated statistically using the Student-test. The in vitro tensile bond strengths of the three bonding agents to dentin showed higher values than the tensile bond strength of composite resin alone and differences among the bond strengths were significant (P < 0.05). Greater bond strength values were obtained with the Gluma bonding system than with Scotchbond or Tenure systems.