<p><strong>Objective:</strong> The aim of this study was to evaluate the effect of mouthrinses on the surface roughness of the nanofilled restorative composite. <strong>Material and Methods</strong>: Twenty discs (4 mm in diameter and 1 mm in height) of the composite Filtek Z350 were made and roughness (µm) was measured using perfilometer with a 0.5 μm diamond needle tip measuring and accuracy of 0.01 μm. The discs were randomly divided into four groups (n=5): Control (distilled water), G1-Plax, G2-Plax Whitening e G3-Listerine and individually storage in eppendorfs with distilled water at 37°C. The specimens were maintained in distilled water during 30 d and immersed in mouthrinses every 12 h for 1 min. after the 30 d the specimens was cleaned in distilled water, storage in oven at 37°C during 24 h and the surface roughness test was repeated with the same parameters previously described. The data were submitted to Two-way ANOVA and the t-studant test for paired specimens. <strong>Results</strong>: No significant differences among groups were detected R1: Control (0.12±0.04); G1 (0.13±0.05); G2 (0.11±0.03); G3 (0.11±0.02); and R2: Control (0.16±0.04); G1 (0.15±0.02); G2 (0.13±0.01) e G3 (0.15±0.02).<strong> Conclusions</strong>: In this study the mouthrinses solutions did not promote significant changes on the surface roughness of Filtek Z350 after 30 d.</p><p><strong>Keywords</strong>: Composites; Polymer; Dental materials</p>