Müllerianosis of the urinary bladder is a rare entity with less than 30 cases reported. It encompasses a mixture of different types of Mullerian lesions like endometriosis, endocervicosis, and endosalpingiosis. It typically affects the women of reproductive age group. The symptoms vary from hematuria and dysuria, to pelvic pain, which may be associated with menstruation. It can mimic a malignant tumor clinically and radiologically; hence, it is important that a correct diagnosis is rendered in these cases to avoid unnecessary radical procedures. Herein we report a case of mullerianosis of the urinary bladder in a young female and discuss the important differential diagnosis and various treatment modalities.