Purpose: The purpose of this study was to retrospectively evaluate the clinical performance of bonded indirect resin composite onlays for the treatment of painful, cracked teeth over a 6-year period. Materials and Methods: Forty-three posterior teeth diagnosed as having a crack were selected in the restorative department of the University of Genoa. Inclusion criteria were sensitivity to biting and cold and a clinically visible crack. Direct composite buildup after removal of the existing restoration was performed before definitive cavity preparation. All composite onlay restorations were cemented with an adhesive technique using a 3-step total etch system and a dual-cure composite cement. Patients were interviewed and clinically examined at 1 week, 4 weeks, and every 6 months. Results: The effectiveness of bonded onlay restorations was evaluated for a mean observation time of 4.78 years. At 1 week, 38 (88.37%) restored teeth were free of pain, 3 (6.98%) still had sensitivity to cold, and 2 (4.65%) still had sensitivity to cold and chewing. At 4 weeks, 40 (93.02%) teeth were free of pain, 2 (4.65%) still had sensitivity to cold and chewing, and 1 (2.32%) needed endodontic treatment. Two other teeth (4.65%) also needed endodontic treatment, the first after 2 months and the second after 5 months. During the evaluation period, 3 restorations (6.98%) failed, and upon clinical examination, 40 (93.02%) teeth were free of symptoms with a 6-year survival rate of 93.02% (life table analysis). Conclusions: Bonded indirect resin composite onlays can be successful in treating painful, cracked teeth. From the findings of this study, it appears that cuspal protection should be incorporated into the design of coronal restorations