Cross-sectional data on permanent tooth eruption were collected by examining the children and adolescents 5-15 years old in a northeastern municipality of Finland. There were 1008 subjects in the whole sample, 483 girls and 525 boys. The results showed statistically significant differences between the girls and boys in timing of eruption of some permanent teeth, indicating earlier eruption in girls than in boys. This difference was most clearly seen in the second phase of the mixed dentition. Interindividual variation in the emergence age was also wider in the second phase of the mixed dentition. The present results seem to indicate earlier eruption of the permanent teeth in rural children in northeastern Finland than in other parts of the country.