Objectives: To analyze the factors influencing pregnancy outcomes in patients with adenomyosis after high intensity focused ultrasound (HIFU) treatment. Design: A retrospective study. Setting: Department of Gynaecology in a single centre in China. Population: Patients with adenomyosis under the age of 45 years who had a desire for future fertility. Methods: Pregnancy outcomes and factors influencing pregnancy outcomes were analyzed using multivariate regression analysis and survival analysis Main Outcome Measures: The improvement of symptoms and reproductive related information were recorded during the average follow-up time of 73.8 ± 28.6 months. Results: After HIFU, 100 of 231 (43.3%) patients became pregnant within 96 months. Among them, 77 conceived naturally, and 23 patients conceived by in vitro fertilization and embryo transfer (IVF-ET). In the 108 infertile patients, 31 (28.7%) became pregnant. At the end of follow-up, 70 successfully delivered 71 healthy babies. No uterine rupture occurred during pregnancy and delivery. The cumulative pregnancy rate increased faster in the IVF-ET group than that in the natural pregnancy group. Patients with pelvic adhesion and infertility history had lower pregnancy possibility than patients without pelvic adhesion and infertility history (OR<1, P<0.05). Patients with small adenomyotic lesion volume had a greater possibility of pregnancy than that of patients with large lesion volume (OR < 1, P < 0.05). Conclusions: HIFU has a positive effect on fertility, and IVF-ET seems to have improved the pregnancy rate of the patients with adenomyosis treated with HIFU. Pelvic adhesion, infertility history, and adenomyotic lesion volume were factors affecting pregnancy.