Undescended testicle is the most common congenital anomaly among males. Testicular tumor develops in 3-5% of the boys with a complaint of undescended testicle. The clinical presentation of malignant intra-abdominal testicular tumors ranges from asymptomatic cases to acute abdomen. In this study, we present a child with testicular tumor rupture which is observed very rarely. A 16-year-old boy presented 24 hours after the sudden onset of right lower quadrant pain, nausea, vomiting and fever. On physical examination, extensive tenderness in the abdomen and abdominal guarding were found. The right testicle was not palpable. The serum white blood cell count was elevated. Ultrasonography and abdominal computerized tomography scan demonstrated a perforated, hyperdense mass with free fluid in the abdomen. The preoperative alpha fetoprotein level was found to be increased. We performed surgery with laparoscopy and a perforated right intraabdominal testicle was found in the right iliac fossa. The mass was excised. Histopathological examination revealed a yolk sac tumor. Ruptured nonpalpable testicular tumors are very rare. To our knowledge, this is the first adolescent case reported so far. Testicular tumor rupture should be considered in patients with nonpalpable testicle and acute abdomen. Laparoscopy may be performed in differential diagnosis and treatment of these patients.