Primary bladder neck obstruction (PBNO) was first described in men by Marion in 1933. The precise cause of PBNO has not been clearly elucidated. This paper review the theories on etiology, clinical presentation, diagnostic evaluation and treatments for PBNO. Also this paper focuses on management of patients with complications like acute urine retention, hydroureteronephrosis and severe renal failure. The treatment options for men and women with PBNO include careful clinical evaluation, pharmacotherapy with alpha-blockers and surgical intervention.