The mechanical properties (diametral tensile strength, compressive strength, modulus of elasticity in compression, Knoop hardness, and Rockwell Superficial indentation and recovery) were measured for one light-cured composite (Herculite XRV) post-cured by five different conditions. The post-curing conditions were: boiling water, CRC-100, D.I.-500, Translux EC Light Box, and Triad 2000 with normal light curing as a control. Post-curing Herculite XRV significantly improved the diametral tensile strength (24-39%), Knoop hardness (8-22%) and Rockwell Superficial recovery (3-6%); decreased Rockwell Superficial indentation (0-19%) but did not affect the compressive strength significantly. Modulus of elasticity was not affected, except by the Translux EC Light Box, which increased the modulus by 33%. Post-curing Herculite XRV with the Triad 2000 and Translux EC Light Box produced the most improved properties. Water at 100 degrees C was the least effective of the post-curing methods.