An intact male pied tamarin (Saguinus bicolor) presented with a hunched posture while moving, dysuria, pollakiuria, and hematuria. After diagnostic imaging assessment and prostate biopsy, benign prostatic hyperplasia was diagnosed. Treatments with delmadinone acetate and osaterone caused clinical signs and hematuria to resolve temporarily for a variable period of time. Because of frequent recurrence, elective surgical castration was performed, leading to resolution of the clinical signs.