In thirty-three newborns with anoxic syndrome was valued the renal injury making use of usual parameters of renal function (Blood urea nitrogen, creatinine, FeNa, Clcr) and furthermore the rate of urinary excretion of beta 2-microglobulin, a marker of tubular damage. All the parameters at the beginning of follow-up were altered. Further monitoring of these showed that BUN, creatinine, FeNa, Clcr were normalized in a short time. Differently beta 2-microglobulin was altered up to the end of follow-up in thirty-one newborns; the values were much lower than original. These results show an high incidence of tubular suffering in the ischemic-anoxic syndrome and a tendency to protract in the time.