Phosphorus-31 (31P) magnetic resonance spectroscopy (MRS) has demonstrated that adenosine triphosphate and phosphocreatine are heterogeneously distributed between gray and white matter in the human brain. However, no studies have reported this characteristic for other phosphorus containing compounds. This study investigated the heterogeneity of phosphorus metabolites using high resolution magnetic resonance imaging (MRI) and 31P magnetic resonance spectroscopic imaging (MRSI) data from the whole brain of thirty-six healthy subjects. Phosphorus-31 metabolite concentrations were plotted against voxel gray matter tissue fraction; linear regression analyses allowed for concentrations of these metabolites to be estimated in homogenous gray and white matter. Results demonstrated differences in bioenergetics and phospholipid metabolism between gray and white matter tissue for the entire cerebrum. Concentrations of adenosine triphosphate, inorganic phosphate, and phosphodiesters were found to be negatively correlated with gray matter tissue fraction while phosphocreatine, phosphomonoesters, and intracellular pH were positively correlated. The concentration of free magnesium was not found to be significantly correlated with gray matter tissue fraction. Similar findings were also observed within the frontal and parietal lobes, although not all correlations were significant.