OBJECTIVE To evaluate the clinical performance of a packable composite resin (Tetric Ceram HB) for posterior restorations of children after 3.5 years, according to Ryge criteria. METHODS Twenty five open apex molar teeth with extensive caries in 21 Iranian patients (8.2 year mean age) were restored by one operator. After caries removal, a layer of calcium hydroxide and glass ionomer base, Fuji II LC were applied. The teeth were restored using an adhesive system, Excite, and flowable composite, Tetric-Flow. The cavities were then restored incrementally with a Tetric Ceram HB. All the 25 restorations were evaluated after 3.5 years by two independent evaluators. Statistical analysis was performed using McNemar test. RESULTS Surface texture for all restorations was classified as excellent. There were no evidence of secondary caries and bulk fracture in any of the restorations. Regarding the items of anatomical form and marginal integrity the statistical analysis reveled a significant difference between the baseline and recall scores respectively (P=0.031 and P=0.031). CONCLUSIONS It was concluded that Tertic Ceram HB exhibited excellent clinical performance after 3.5 years in the open apex first permanent molar teeth.