Using the inversion transfer technique, the possible magnetic coupling between water protons and the protons of low-molecular weight metabolites was investigated in human brain and skeletal muscle at 1.5 T. The localized 1H-MR spectra were recorded at different times after selective inversion of the water resonance. Water inversion led to a significant transient reduction in the signal intensity of the methyl protons of creatine/phosphocreatine, in both tissues. This is indicative of magnetic coupling between the protons of water and those of creatine/phosphocreatine. Neither the choline and N-acetylaspartate protons in brain nor the protons of the trimethylammonium pool in skeletal muscle showed a significant magnetic coupling to mobile water. Copyright © 2001 John Wiley & Sons, Ltd.