Carbon dioxide laser energy has been shown to possess the ability of enhancing dentinal bond strength of a recently introduced dentinal bonding agent. It is presently unclear as to whether Nd-YAG laser energy can have the same effect. The objective of this study was to measure the effect of Nd-YAG laser pretreatment of dentin on the dentinal bond strength. Thirty extracted molars were mounted vertically in an acrylic base, to a depth of their cervical lines. The bottom of the base was flattened, and a plane perpendicular to this base was ground into one buckle surface of each molar. This exposed a dentin surface 6 mm or greater in diameter. These teeth were randomly distributed into two groups, with 15 teeth per group. Brass rings of approximately 5 mm in diameter were placed on these flat surfaces, and filled using Scotchbond 2 (3M) and P-50 (3M) composite material as per manufacturer's instructions. The experimental group was treated identically to the control group with the exception of laser treatment of the dentin at 51 Watts/cm2 for 0.2 sec. before application of Scotchbond 2. After curing, these restorations were shear tested using an Instron machine at 0.1 in/min. crosshead speed. The mean shear strength and standard deviation for the control group were 1.29, 1.74 MPa, and for the irradiated group 1.05, and 1.07 MPa, respectively. Students t-test found no significant difference (P equals 0.2914) between the groups. It does not appear that, at these powers, the Nd-YAG laser possesses the ability to enhance the bond strength of Scotchbond 2 dentinal bonding agent.