The purpose of our study was to examine the nationwide trends in the age- and sex-specific incidence rates of fatal injuries among 10-19-year-old adolescents in Finland, a country with a well-defined white population of 5.2 million. A population-based study was based on Official Cause-of-Death Statistics of Finland. We included adolescents aged 10-19 years who died because of an injury in 1971-2002. During the study period, the incidence of injury-related deaths declined considerably, from 43.0 (per 100,000 persons) (95% confidence interval (CI): 38.5, 47.5) in 1971 to 19.9 (95% CI: 16.5, 23.4) in 2002 (p<0.001). The decrease was seen in both genders. The decline in injury deaths was mainly due to decrease of deaths in traffic accidents. A sharp peak in boys' suicides was found during economic depression. To sum up, the incidence of adolescent injury deaths declined considerably in Finland between 1971 and 2002. The reasons for this positive development are probably multifactorial, including improvements in traffic safety and emergency services. The trend in intentional deaths showed no change during the 32-year study period and therefore prevention of adolescent violence and suicides should also receive attention.