Class II restorations of six light cured posterior composite resin materials (the intermediates Occlusin, P 30, Fulfil, Profile and the microfine Heliomolar and Distalite) were followed for five years. The results from three years have been reported earlier (Lundin et al 1990). At baseline twenty-four dentists from seven different clinics of the Public Dental Health Services in the country of Bohuslän placed 247 Class II restorations on 213 patients of the ordinary clientele visiting the clinics. Before starting the operators were instructed and trained in performing the restorations according to a standardized clinical procedure. The restorations were evaluated, according to a specially designed assessment form using the USPHS criteria, after one week, three years and five years. Stone casts were used to quantitatively categorize the occlusal wear according to the Leinfelder method. After five years the failure rate (USPHS rating Charlie) was 27 restorations out of assessed 176, i.e. 15%. The most common reason for failure was secondary caries. Fulfil had the highest failure rate among the intermediate materials (Chi-Square, p < 0.05). Assessment of wear showed that Profile, compared to the other intermediate materials, had worn the most and the two microfine materials Heliomolar and Distalite, compared to all the intermediate materials had worn the least. This study confirms the results from three years, that clinically acceptable results can be obtained with posterior composite resin materials when used in a proper and scheduled manner.