The aim of the study was to introduce an individual tooth wear index and to use this index to investigate factors correlated to occlusal wear. The material consisted of 585 randomly selected dentate individuals from the community of Jnkping, Sweden, who in 1983 reached the age of 20, 30, 40, 50, 60, 70, or 80 years. The degree of incisal and occlusal wear was evaluated for each single tooth in accordance with criteria presented earlier. An individual tooth wear index, which made it possible to rank individuals in accordance with incisal and occlusal wear, was used as dependent variable to investigate factors related to incisal and occlusal wear. Of all factors analyzed, the following were found to correlate significantly with increased incisal and occlusal wear: number of existing teeth, age, sex, occurrence of bruxism, use of snuff, and saliva buffer capacity. Stepwise multiple regression analysis gave a total explanation factor of R² = 0.41. It was also possible to distinguish well between groups of individuals with and without tooth wear by means of these factors.