The case of two female patients with de novo terminal deletion of the long arm of chromosome 10, one with del(10)(q26.2) and the other with del(10)(q26.3), is reported. Both presented with megabladder associated with urinary tract abnormalities. The case of four similar patients has been previously reported with bladder dilatation secondary to urinary obstruction. These new cases highlight the possible involvement of the bladder and the urethra in the syndrome of chromosome 10q terminal deletion, suggesting a careful renal and urinary tract evaluation in such situations. Moreover, the possibility of monosomy 10qter syndrome should be borne in mind in the case of prenatal diagnosis of apparently isolated bladder obstruction, especially in females.