Most congenital mesoblastic nephromas were asymptomatic abdominal masses, although some could cause hematuria, hypertension, or hypercalcemia. This was the first case of neonatal dyspnea caused by fast tumor development in an early-birth neonate. Ultrasonography revealed a kidney tumor and polyhydramnios in a male fetus at 32 weeks and 3 days of pregnancy. Due to the polyhydramnios, the woman exhibited abdominal distension and symptoms of impending premature birth. The symptoms of impending preterm birth faded after amniocentesis, but the growth of the kidney tumor was identified as a possible reason for respiratory failure. A cesarean section was performed at 36 weeks and 2 days of pregnancy. His birth weight was 2,638 g, and his APGAR scores at 1 and 5 minutes were 2 and 4, respectively. The patient didn’t breathe on his during birth, and had a lot of abdominal distention. Cardiopulmonary resuscitation was performed on the patient. After circulation stabilized, emergency surgery was conducted due to increasing hypoxemia and respiratory acidosis. A large tumor growing from the right kidney was discovered during a laparotomy, and a right nephrectomy was performed. The diagnosis of congenital mesoblastic nephroma was made after a histopathological study. After the tumor’s pressure on the thorax was alleviated by surgery, the patient’s respiratory status and circulatory dynamics normalized. The recovery period was unremarkable. There have been no recurrences or problems in the 36 months since the surgery. Although there was a fair prognosis, congenital mesoblastic nephroma can rapidly grow in size from the fetal period and may trigger a pulmonary oncologic emergency.