The purpose of this study was to evaluate the survival of 525 composite indirect restorations in premolars and molars after a follow-up of 20 years. For each patient, the following variables were recorded and analyzed: age, sex, smoking status, presence of plaque according to O'Leary index, and presence of bruxism. For each restoration, the following variables were collected: restoration class, tooth type (premolar or molar), and restoration material. Mean 20-year survival rate of composite restorations was 57%, ranging from 44% to 75%. The Kaplan- Meier method demonstrated a probability of survival at 10 years of 80% and 90%. Surviving restorations kept their clinical characteristics extremely well, as assessed on the basis of the United States Public Health Service criteria. The results of this study demonstrate the efficacy of indirect composite restorations, confirming their reliability as a posterior prosthetic clinical option.