Beta-HCG in serum was analysed in 64 cases of ectopic tubal pregnancy who wree different groups; ruptured ectopic pregnancy, ectopic pregnancy accompanied by amenorrhea or adnexal mass and ectopic pregnancy without palpable adnexal mass and amenorrhea. The mean HCG levels for the three groups were 8 790 IU/l, 2 580 IU/l and 690 IU/l, respectively, which related more to the symptoms than to the estimated length of pregnancy. Eleven per cent of the women had an IUD and five per cent were taking low dose gestagens. Screening of cases with acute lower abdominal pain or irregular vaginal bleeding with beta-HCG in serum will facilitate an early diagnosis of ectopic pregnancy and be of special value in patients with less typical symptoms.