A study of the effect of a long-acting injectable contraceptive composed of a progestogen-estrogen combination (Deladroxate) on subsequent fertility was carried out. 78 multiparous females (18-40 years) were followed up monthly for 12-14 medication cycles and 6 months after cessation. Ovulation occurrence was determined by endometrial biopsy. Pregnancy was diagnosed clinically and by the immunological detection of chorionic gonadotrophins by the Gravindex test. The average cycle length was 26.8 days premedicationally & the average cycle length was 26.3 days during therapy. The average cycle length in the first six post-cessation cycles was 29.1, 27.5, 25.6, 25.3, 25.4, and 26.1, respectively.  The average duration of flow was 4.5 days premedication ally. It was 8.2 days during therapy. After cessation, the average flow duration in the first six cycles was 6.7, 6.1, 5.6, 5.3, 5.4, and 4.8, respectively. Differences in the amount of flow before and during medication were not significant. Follow-up of the amount of flow in the first six post-cessation cycles showed a drop in both heavy and scanty flow and a rise in the percentage of average flow. None of the cases experienced intermenstrual bleeding before medication. Breakthrough bleeding was experienced in 2.8% of cases during medication. After cessation, breakthrough bleeding in the first six cycles was 18.3, 17.1, 10.2, 9.1, 7.2, and 2.1% of cases, respectively. Endometrial biopsies obtained from 15 cases during the last treatment cycle proved that none was ovulating. Post-cessation biopsies from those 15 cases in the first 6 cycles showed secretory changes in 3 out of 15, 3 out of 14, 6 out of 14, 5 out of 13, 7 out of 12, and 8 out of 12 cases, respectively. None of the cases fell pregnant during medication or the first post-cessation cycle. 2, 4, 4, 3, and 2 pregnancies were encountered from the second to the 6th post cessation cycle. Thus 15 pregnancies occurred during the 6 Post Cessation cycles. Two pregnant cases were followed up to term and had normal, uneventful pregnancies and deliveries. Both infants were examined after delivery and were found normal.