Early-stage endometriosis is a known contributing factor for chronic pelvic pain and sub-fertility. To determine whether Helica Thermal Coagulation is an effective short-and long-term treatment for endometriosis-associated chronic pelvic pain and sub-fertility. Thirty six patients were followed up from 6 weeks to 1 year post-Helica treatment of early endometriosis. Pain relief was assessed subjectively. Eight of the women suffered from sub-fertility in addition to pelvic pain, while three patients suffered from sub-fertility alone. Ninety-three percent were pain free at 6 weeks, 75 % were pain free at 6 months and 37.5 % remained pain free at 1-year follow-up. Of those who continued to have pain at 1-year follow-up, three had repeated Helica treatment, two had hysterectomy and bilateral salpingoopherectomy, and the rest were commenced on different hormonal treatment to control endometriosis. Ten women (62 %) conceived within 1 year of treatment. Helica coagulation seems to be an effective way of treating early endometriosis-associated pelvic pain and sub-fertility. However, its effects only seem to be short term, with a decline in symptom relief and pregnancy rate over the 12-month postoperative period. Larger RCT are required.