Mullerianosis is a rare, benign, and morphologically complex, tumor-like lesion that consists of an organoid structure with normal Müllerian tissue. The diagnosis requires the presence of at least two of the three mullerian tissues: endometriosis, endosalpingiosis, and endocervicosis. There are only less than twenty (20) cases reported in literature. At present there is no published case report of mullerianosis here in the Philippines. This is a case report of a 30-year old Filipino woman who presented predominantly with lower urinary tract symptoms of severe dysuria, hematuria, and lumbar pain and was evaluated for a urologic problem secondary to a posterior bladder mass. Subsequent evaluations revealed the diagnosis of mullerianosis. This is where the interest in mullerianosis sets, its potential to mimic a neoplastic lesion of the urinary tract from clinical and diagnostic viewpoints. The clinical importance to diagnose this case correctly is of grave importance for appropriate management.