Hospitalization for ectopic pregnancy was examined in 15 out of 19 Norwegian counties in 1986. The incidence of ectopic pregnancy was 1.5 per 1,000 women aged 15-44 years. The incidence was highest in the five northernmost counties and Oslo. Women aged 25-34 years, who had the highest rate of conception, also had the highest rate of ectopic pregnancy. Measured as a ratio per 100 live births, ectopic pregnancy increased with the patient's age and was six times as high among women aged 35-44 compared to women aged 15-24. The overall ratio was 2.5 ectopics per 100 live births. The age-specific rates and ratios were consistent with varying overall incidence of ectopic pregnancy in the counties.