Interstitial pregnancy is the least frequent variety of tubal gestation, but its occurrence is far from rare. There were 568 cases of ectopic pregnancy treated at S.R.C.H from Jan., 1968 to Jun, 1974 of which 14 were inerstitial pregnancy an incidence of 2.5%. Most reported statistics place its incidence at from 1.1% to 6.3% of all extruterine pregnancy. In this series of interstitial pregnancy, there was no maternal death and perforation occured between sixth and thirteenth weeks of gestation, contrary to the general impression of late pregnancy.