Objective: To assess the 10-year clinical performance of resin composite restorations placed using the acid-etch technique. Method and Materials: Clinical evaluation of 58 resin composite restorations was performed by 9 operators of the Operative Dentistry Clinic of the Dental Hospital, Tokyo Medical and Dental University. Conservative preparations had been made and a total-etch adhesive system used for the resin composite restorations, which were placed in 1992 in the Operative Dentistry Clinic. Restorations were scored using the following scale: Alfa-good; Bravo-clinically acceptable; Charlie-clinically unacceptable; Delta-already replaced. The scores were analyzed using the chi-square test and the expected cell frequency (P = .05). Results: The 58 restorations from 26 patients (13 men and 13 women) were identified in the treatment records and analyzed. Twenty-two restorations (37.9%) presented Alfa scores and 17 restorations (29.3%) were clinically acceptable (Bravo scores), while 3 restorations (5.2%) received Charlie scores and 16 restorations (27.6%) had already been replaced (Delta scores). The descending ranking of longevity by restoration type was Class 5 > Class 3 > Class 2 > Class 1 > Class 4 (P = .05). Conclusions: Of the restorations evaluated, 67.2% were serviceable (combined Alfa and Bravo scores) 10 years after placement. Longevity was significantly influenced by cavity type Keywords: acid etching, clinical evaluation, dentin bonding system, longevity, resin composite, retrospective study