Objective: This clinical trial aimed at studying the long-term performance in routine clinical practice of saucer-shaped Class II resin composite restorations. Method and materials: Fifty-one preparations were completed and filled with either of two light-cured posterior composites by seven dentists of the Public Dental Service. The restorations were evaluated annually, using the US Public Health Service criteria, bitewing radiographs, and dies based on replica impressions. At the final evaluation, the recall rate ws 100%. Results: After a meanof 7.2 ± 1.3 years of service (censored maximum of 9.6 years), 70% of the restorations were acceptable for continued use. Caries and technical deficiencies were the main causes of failure. Conclusion: The saucer configuration, by respecting and utilizing inherent properties of the resin composites, spares sound dentin and is preferable to the box preparation