The metabolic fate of 51Cr-β-glycerophosphate complex, a newly developed radiocompound that accumulates in tumor tissue, has been studied. Determinations of 51Cr uptake and phosphatase activity in the tissues indicate that in tumor the chromium accumulation is not due to simple phosphomonoesterase action. The phosphate ester isolations indicate that the fate of chromium is closely related to that of the β-glycerophosphate molecul