Recently, purine degradation products, especially hypoxanthine, have been studied in relation to perinatal asphyxia. However the final degradation product, uric acid (UA) received little attention. We previously showed a correlation between cord UA levels and Apgar scores in a low risk population. Here we report on serum UA concentrations in relation to perinatal asphyxia. During a period of half a year serum UA and creatinine (CREA) concentrations were measured in blood samples taken from 275 newborns admitted to the NICU in Leuven. In 67 patients, UA and CREA were also measured in a urine sample on the first day of life. A negative correlation was found between the 1 min Apgar score and both the maximal serum UA concentration in the first 24h (r= -0.23, p< 0.025) and the corrected excretion of UA = (urineUA × serumCREA)/urineCREA (r= -0.45, p<0.005). All newborns were classified as normal, moderate or severe with respect to perinatal asphyxia. Newborns with severe asphyxia (n = 14) needed to have obvious neurological and cerebral ultrasound abnormalities at discharge. No significant differences were found in serum UA levels between the groups on the day of birth and the day thereafter due to the large variation in the normal group (303±71 and 351 ± 172 μmol/l). However, on each of the days 2 to 10, serum UA levels were significantly (p<0.05) higher in the severe asphyxia group compared to the other groups. Moreover, all 13 newborns with severe asphyxia who had serum UA measured on day 2 or later had values higher than the normal range (defined as mean + 2SD of the normal group: 357, 297 and 172 μmol/l on days 2,3 and 4). We conclude that newborns with severe perinatal asphyxia have increased levels of serum UA between days 2 and 10 of life.