OBJECTIVE: To investigate, in vitro, the influence of at-home bleaching with 16% carbamide peroxide (CP) gels containing different thickeners on the color, gloss, roughness, and microhardness of a composite resin with bisphenol A (BPA) and without bisphenol A (BPA-free). MATERIAL AND METHODS: Cylindrical samples (7 × 2 mm) of a composite resin with BPA (Filtek Z350 XT®; 3M/ESPE) and composite resin BPA-free (Vittra APS®; FGM) were subdivided into six subgroups (n = 12), according to the bleaching gel used: no bleaching (control), commercial gel with 16% CP and carbopol, experimental gel with 16% CP and carbopol, experimental gel with 16% CP and natrosol, experimental gel with carbopol and experimental gel with natrosol. At the end of the experimental phase, the specimens were analyzed for color (ΔE*ab and ΔE00 ), surface roughness (Ra), gloss (GU), and surface microhardness (SMH). The data for all analyzes were submitted to Levene's test, Shapiro-Wilk's test and ANOVA. RESULTS: For ΔE*ab and ΔE00 no statistically significant differences were found between all groups evaluated. Bleaching with experimental 16% CP gel with carbopol resulted in the lowest GU values for both composite resins evaluated. 16% CP experimental gel with natrosol resulted in higher Ra for the BPA composite resin and the bleaching with natrosol resulted in higher Ra for BPA-free. About 16% CP experimental gel with carbopol and 16% CP experimental gel with natrosol resulted in the lowest final SMH for composite resin with BPA. For the BPA-free composite resin, no differences were found between the groups in SMH for the same resin, however they presented the lowest values compared with all others groups. CONCLUSION: The effects on physical properties are dependent on the composition of the composite resin and the thickener/bleaching gel used. The BPA-free composite resin showed less changes after exposure to bleaching agent, although its initial physical properties were worse compared to a bleached BPA. CLINICAL RELEVANCE: The hydrogen peroxide and thickener of the at-home bleaching gel does impact the properties of composites with BPA or BPA-free such as gloss, roughness and surface microhardness, extremely important factors for maintaining an aesthetically and physically satisfactory restoration. BPA-free composite resins have inferior properties after at-home bleaching with different thickeners.