The 24-hour shear bond strength of two dentine bonding agents was determined under two conditions. In the first, the adhesive bonding resin was cured prior to placing and curing the composite. In the second, the adhesive resin and composite were cured together. Significantly greater bond strength values were obtained for both materials using the first conditions. These differences in bonding characteristics are likely to be significant from a clinical viewpoint as well as from a statistical viewpoint. It is concluded that there is a need to establish the adhesive-dentine bond before applying and curing the composite.