Objective: The analysis of reasons for the replacement of 9,805 amalgam, composite, glass ionomer, resin modified glass ionomer and ‘other’ restorations in permanent teeth in general dental practice. Design: The data were subdivided on the bases of age and gender of the patients, the types of restorations and the clinicians' gender, experience and practice setting. Results: The clinical diagnosis of secondary caries was the main reason for replacement of all types of restorations studied, followed by fracture of restorations, especially bulk fracture, irrespective of patient's age. Bulk discolouration was the third most common reason for replacement of resin based materials in adults, but it rarely occurred in adolescents 18 years and younger. The reasons for replacement of restorations were not associated with the gender of the patients. Subgroupings based on the clinicians' gender showed that female clinicians diagnosed secondary caries more often than male clinicians. Otherwise, the reasons for replacements were similar for both genders of clinicians. Subdivision of restorations based on the years since graduation of the clinicians resulted in small groups. The youngest group of clinicians diagnosed relatively more secondary caries both for amalgam and composite restorations than the most experienced group. Conclusion: The clinical diagnosis secondary caries was the main reason for replacement of all types of restorations studied.