BACKGROUND The relatively large adrenal glands of the newborn are vulnerable to mechanical trauma during delivery. Great birth weight, difficult labor, perinatal hypoxia and prematurity are predisposing factors of adrenal haemorrhage. Minor adrenal haemorrhage may not cause symptoms. Massive adrenal haemorrhage is uncommon. Symptoms include anaemia and jaundice associated with a suprarenal mass. In cases with severe blood loss acute shock may develop. In 5 to 10 per cent of cases the haemorrhage is bilateral. Ultrasonography has replaced urography in the diagnosis of this condition demonstrating the site and size of the lesion and allowing an accurate follow-up. Within a month after haemorrhage the blood and necrotic adrenal tissue are resorbed and thin calcification appears at the periphery of the gland. Surgery is necessary if haemorrhagic pseudocyst is large and does not resorb spontaneously. METHODS From 1992 to 1996, five patients with neonatal adrenal haemorrhage were treated at the University Children's Hospital in Belgrade. Two of them were females. All patients were born at term by vaginal delivery. Their birth weights ranged between 3200 and 4050 g. At hospitalization infants were aged from 6 hours to 18 days. The first symptom of adrenal haemorrhage was an abdominal mass in three patients. One of them had laparoschisis with guts and stomach protruding out; the surgeon discovered a mass in the right retroperitoneum during operation. Two patients had jaundice associated with anaemia, and sepsis another two. Ultrasonography was done in all patients. We punctured the haemorrhagic pseudocyst (diameter above 5 cm) in three patients and made cystography. Liquid components of pseudocysts were aspirated and sent to bacteriological and cytological analyses. RESULTS The diagnosis of adrenal haemorrhage was confirmed by ultrasonography in all patients, demonstrating a right adrenal mass (unilateral in all patients), mostly hypoechoic, which displaced the right kidney. Calcification at the periphery of the pseudocyst appeared in one patient. The adrenal haemorrhage disappeared spontaneously in two patients after two months. An attempt to support the adrenal hemorrhagic pseudocystic regression by puncturing and aspirating its content in three patients was successful in one infant. The patient with laparoschisis died because of sepsis and thrombocytopenia. In a patient the haemorrhagic pseudocyst persisted (6 cm in diameter) and was surgically removed. CONCLUSIONS Ultrasound is the method of choice in the diagnosis of adrenal haemorrhage, antenatally and neonatally. It also allows diagnosis of coexisting complications such as renal vein or inferior vena cava thrombosis and a proper follow-up. Puncture of pseudocyst and aspiration of liquid components may support involution of large haemorrhagic pseudocysts. If it is unsuccessful, surgery is necessary.