Cerebral metabolic abnormalities have been previously detected by 1H-MRS in infants with the Zellweger syndrome as young as 3 months. We hypothesized that metabolic abnormalities could also be found shortly after birth. Two fullterm infants with Zellweger syndrome were studied at 12 days and two months of age, respectively, using single voxel 1H-MRS. In the first case 1H-MRS was performed using PRESS with variable TE (31, 136, 272 ms); in the second, STEAM and PRESS sequences were used with different TE (STEAM at 30 and 144 ms; PRESS at 270 ms). In both cases a significant decrease of N-acetylaspartate (NAA) and an abnormal signal at 1.33 and 0.9 ppm, consisting of lactate (Lac) and lipids (Lip) were found. The reported MRS abnormalities, although not specific for peroxisomal dysfunctions, may support the suspicion of Zellweger syndrome and may indicate direct referral to the specific laboratory and molecular studies necessary to establish the diagnosis and prognosis of this syndrome.