Objective: To evaluate the feasibility and the effect of a conservative modified surgical technique performed at laparotomy in a group of patients with diffuse adenomyosis diagnosed at MRI. Methods: Retrospective analysis of conservative surgical treatment in 44 women with diffuse adenomyosis diagnosed on pelvic examination by an enlarged uterus and by MRI with a hypertrophy of the anterior and posterior walls with loss of the junctional zone. All women desired strongly to avoid hysterectomy. Mean age of the patients was 37.1±3.8y (range 29–45 y). Dysmenorrhea and abnormal uterine bleeding were the main complaints. An asymmetric longitudinal incision was performed sacrificing one Fallopian tube as it was cut at the interstitial portion. The serosal incision formed a line between the height of the internal os at the anterior/posterior wall and the uterine fundus. From this incision the myometrium was dissected diagonally as if hollowing out the uterine cavity. After transverse opening of the uterine cavity the adenomyosis lesion was excised to a thickness of 5 mm of the inner myometrium. The lesion was then excised to a thickness of 5 mm of the serosal myometrium. Consecutively the uterine cavity was closed followed by uterine rejoining with the left side covering the right side. Results: Histological examinations revealed the presence of adenomyosis in all patients. For dysmenorrhea the mean visual analogue scale decreased from 9.4±1.0 before the intervention till 0.8±1.0 postoperatively. Postoperative blood loss decreased in all women and anaemia improved in all of them. Mean operation time was 159±43.7 min. Seven patients required transfusion. No postoperative complications occurred and none of the patients showed an Asherman syndrome. One year after surgery 3 of 32 women had recurrence of dysmenorrhea. One woman has an evolutive pregnancy after IVF treatment. Conclusion: The surgical procedure provides dramatic relief from dysmenorrhea and improves anaemia. The procedure is indicated in those women wanting a relief of their symptoms while preserving the uterus, but is less indicated in women wanting to become pregnant.