Objective: The objective of this study was to evaluate the clinical performance of two packable and one microhybrid resin composites placed in occlusal cavities of posterior permanent teeth after 1 year. Method and materials: Sixty occlusal restorations were placed in 18 male or female patients aged 21 to 44 years. The restorations were divided into three groups according to the restorative material: G1 (Surefil + Prime&Bond NT); G2 (Filtek P60 + Singlebond), and G3 (Suprafill + Suprafill). They were placed by two previously calibrated operators. The restorations were directly evaluated for color matching, marginal discoloration, secondary caries, wear, marginal adaptation, and postoperative sensitivity. Results: Of the total restorations, 66.7% were scored A (ideal) for color matching; 98.2% for marginal discoloration; 100% for secondary caries; 92.6% for wear; and 92.6% for marginal adaptation. Postoperative sensitivity was reported in 5% of the restorations. Fisher's exact, McNamara's, and chi-square tests did not indicate statistical difference between the groups, related to the evaluated criteria. Conclusions: The packable (Filtek P60 and Surefil) and the microhybrid (Suprafill) resin composites exhibited excellent clinical performance after 1 year and may be considered possible materials for the restoration of posterior teeth. Keywords: Class I restoration, clinical evaluation, color, dental caries, dental restoration, dentinal sensitivity, marginal adaptation, resin composite, tooth discoloration, wear