Endometriosis recurrence after conservative surgery is not infrequent. Variable regimens of hormonal therapy have been proposed as adjuvant post-operative measures for prophylaxis against recurrence. Among these, the combined oral contraceptive pills (OCP), represents a valuable option in terms of safety and tolerability for long-term use. The objective of this review is to evaluate the effect of post-operative use of OCP in preventing symptom recurrence, and/or anatomical relapse of endometriosis. A systematic search of Medline identified seven studies evaluating post-operative OCP treatment on prevention of endometriosis recurrence. A reduction in anatomical relapse rate was observed when oral contraceptive therapy was administered for more than 1 year after conservative surgery. Post-operative use of OCP was associated with a reduction in frequency and intensity of dysmenorrhoea recurrence. No association was found between OCP therapy and dyspareunia prevention, although the effect of OCP on chronic pelvic pain was conflicting. Long-term OCP therapy can be a reliable adjuvant post-operative measure to prevent or reduce frequency/severity of recurrent dysmenorrhoea and anatomical relapse of endometriosis. Since both continuous and cyclic OCP administration regimens seem to have comparable effects, the choice of regimen can be modulated according to patient preferences. The protective effect seems to be related to the duration of treatment.