Two newborns, male and female from the same mother, died at 10 and 45 minutes of life respectively, and underwent post-mortem examination. The first of the corpses, corresponding to the female, was referred with the clinical judgement of severe respiratory failure with suspected Potter's Syndrome and severe oligohydramnios; she was born by emergency caesarean section due to breech presentation and the Apgar test was 1/3/7; minutes later she died. External examination revealed a subcyanotic colour, triangular facies with mongoloid parpebral fissures, micrognathia, broad nasal root and prominent occiput. The abdomen, globular, hard and slightly dented, allowed the palpation of two large masses occupying both renal fossae and hemiabdomenes. When the cavities were opened, the presence of two large renal masses measuring 10 x 8 x 5.5 cm and 12 x 8 x 6 cm with weights of 190 and 235 g respectively, stood out. Although the renal silhouette could be discerned, the surface, dented, showed numerous cystic formations of serous content; when cut, these cysts were heterogeneous in size, with those located at the cortical level being larger, giving the kidney a sponge-like appearance. The right and left lungs weighed 17 and 15 grams (usual weight of the set of 49 grams) showing a uniform reddish hue; both were compressed as a result of the diaphragmatic elevation conditioned by the large size of the kidneys. The rest of the organs showed no significant macroscopic alterations except for the positional alterations derived from the renal compression. In the second carcass, the male, similar morphological changes were observed, although the size of the kidneys was even larger, with weights of 300 and 310 grams. The rest of the abdominal viscera were compressed against the diaphragm. In both cases, a detailed histological study was performed, focusing especially on the kidneys where multiple cysts of different sizes with saccular morphology were demonstrated at the cortical level. These cysts occupied most of the corticomedullary parenchyma, although the preserved areas showed no significant alterations except for focal immaturity. These cysts were lined by a simple epithelium varying from flat to cubic. The smaller, more rounded medullary cysts were lined by a predominantly cubic epithelium. After the renal cysts, the most striking alterations were found in the liver where proliferation and dilatation, even cystic, of the bile ducts at the level of the portal spaces were observed. These findings led to a diagnosis of autosomal recessive polycystic kidney disease in both cases.