AIM: The objective of the study was to report the endometriosis case and surgical technique to reduce the diminished ovarian reserve risk. CASE PRESENTATION: A 32-year-old woman was presented with the lower abdominal pain since 1 year ago, intermittent, and got worse during menstruation. The mobile cystic mass was palpable on the abdomen without pain during palpation. Vaginal examination showed mobile and smooth surface cystic mass was palpable, the upper pole was three fingers below the umbilicus, and lower pole was in line with pubic symphysis. Transvaginal ultrasonography (TVUS) showed uterus and right ovary enlargement; and unilocular cyst with homogenous echo pattern. There was a marked increase in CA-125. Based on International Tumor Analysis, the tumor was classified as B1 unilocular cyst and the malignancy risk index was 600. The patient was diagnosed with endometriosis and laparotomy cystectomy was performed. CONCLUSION: Patient was diagnosed with endometrial cyst and laparotomy cystectomy was performed as treatment. Ovarian cystectomy in infertile women was shown to have comparable ovarian reserve (OR), reduced pain symptoms, and increased conception among infertile patients.