Purpose: The aim of this study was to evaluate the effect of home care whitening methods on surface roughness of low shrinkage composite. Methods: One hundred and twenty discs of low shrinkage (Filtek P90) were fabricated. Discs were divided into four groups according to the whitening agents (5% hydrogen peroxide, sodium bicarbonate and whitening toothpaste) with control group brushed with distilled water only. Then the discs subdivided into three groups according to storage time in distilled water to (one day, three months and six months). The whitening agents were applied two minute per day by toothbrush stimulator apparatus. Ra values were determined by digital microscope with software program. Statistical analysis was performed by using ANOVA and Tukey's test.  Results: The home care whitening agents significantly increased the surface roughness of low shrinkage composite, when the storage in distilled water caused decreasing of the surface roughness of low shrinkage composite. Conclusions: The home care whitening agents and the storage in distilled water had a significant effect on the surface roughness of low shrinkage composite.