The relative concentrations of inorganic phosphate and phosphomonoesters (PME) of 18 human cadaveric kidneys stored in Euro-Collins perfusion solution were measured by 31P MR spectroscopy. The signals of intracellular inorganic phosphate (Pii) and inorganic phosphate contained in the perfusion solution (Pie) were separated by the deconvolution technique. The ratio of the signal intensities of phosphomonoesters and intracellular inorganic phosphate (PME/Pii) was used as a marker of kidney viability and correlated with kidney function after transplantation. Separation of the Pii and Pie signals in the measured spectra was successful in 72% of kidneys. The results of MR analysis satisfactorily agree in 78% with the post-transplant function of kidneys.