Purpose: Lithium disilicate (LDS) glass-ceramic restorations are routinely used, but results over a period longer than 10 years are rare. The objective of this study was to obtain long-term clinical data on monolithic LDS posterior crowns provided by a single restorative dentist. Materials and Methods: Eligible patients who received a circumferential LDS crown in the posterior region between 1997 and 2010 were invited to participate in a clinical examination in 2015. This consisted of intraoral inspection and radiographs, performed by one observer and according to standardized criteria. Probability of survival was estimated using Kaplan-Meier survival analysis. Results: A total of 13 patients (n = 87 restorations) fulfilled the inclusion criteria. Of these, 12 patients were available for clinical evaluation (n = 74 restorations). After 5, 10, and 15 years, the cumulative chance of survival of the restoration was 92%, 85.5%, and 81.9%, respectively, with a median observation period of 12.8 years. Of the 74 restorations, 13 failed: 4 because of secondary caries, 2 because of debonding, and 7 because of fracture of the restoration. Conclusion: Lithium disilicate can be regarded as a strong and fracture-load-resistant restorative material providing reliable long-term clinical performance.