The cerebellar hemispheres (CER) are different from the supratentorial white and gray matter embryologically, in cytoarchitecture, and probably in metabolic activity. Proton magnetic resonance spectroscopy ((1)H MRS) can provide a noninvasive biochemical analysis of this region.To study, with (1)H MRS, metabolite concentrations in CER as a function of age and compare these metabolic data with those of parietoccipital white matter (PO WM) in healthy children.Using single-voxel (1)H MRS, we studied 37 volunteers (3-18 years) with normal MRI scans of the brain. (1)H MRS was performed using the PRESS technique in CER and PO WM. The NAA/Cr, Cho/Cr, NAA/H(2)O, Cr/H(2)O, and Cho/H(2)O ratios were analyzed as a function of age. Metabolic data from these regions were compared.The NAA/Cr ratio tended to increase with age in CER. Mean NAA/Cr and Cho/Cr ratios were found to be lower in CER than in PO WM. Mean NAA/H(2)O, Cr/H(2)O, and Cho/H(2)O ratios in CER were higher than in the PO WM.Our data confirm the regional variations between CER and PO WM metabolite ratios, and demonstrate a tendency of age-dependent change of the NAA/Cr ratio in CER. The creatine concentration was significantly higher in the cerebellum than in the PO WM.