OBJECTIVE To present a case involving pregnancies in a Turner woman with Y-chromosome mosaicism. METHODS A descriptive case report of a single patient. RESULTS A 39-year-old woman was admitted to the endocrine clinic due to fatigue and premature menopause. She had tried in-vitro fertilization and oocyte donation twice without pregnancies but became spontaneously pregnant at age 36 and 37 and delivered two girls. During the seventh month of the second pregnancy, a dissecting aortic aneurysm, a coarctation, and subsequently a pheochromocytoma were detected and repaired. Hypothyroidism developed. Turner syndrome was diagnosed. Fluorescence in situ hybridization (FISH) analysis of lymphocytes revealed 31% XY cells and 4% XYY cells, while 66% of buccal cells had an XY constitution. Oophorectomy revealed no malignancy. FISH revealed 54% XY cells in the left gonad and 38% XY cells in the right. CONCLUSIONS Turner syndrome should be suspected in women with aortic dissection, in general, but especially in those with additional features such as horseshoe kidney, coarctation, and infertility.