High-resolution magic angle spinning (MAS) 1H NMR spectra of small samples (ca. 8 mg) of intact rat liver are reported for the first time. One dimensional spectra reveal a number of large well-resolved NMR signals mainly from low to medium molecular weight compounds (generally <1000 Daltons) from a variety of chemical classes. A range of 2D MAS-NMR experiments were performed, including 1H J-resolved (JRES), 1H-1H total correlation spectroscopy (TOCSY) and 1H-13C heteronuclear multiple quantum coherence (HMQC) to enable detailed signal assignment. Resonances were assigned from α- and β-glucose, glycerol, alanine, glutamate, glycine, dimethylglycine, lysine, and threonine, together with phosphocholine, choline, lactate, trimethylamine-N-oxide (TMAO), and certain fatty acids. Well-resolved 1H NMR signals from glycogen (poly 1-4 α-glucose) were observed directly in intact liver using MAS-NMR spectroscopy. In addition, the resonances from the glycogen C1H proton in α(1→4) linked glucose units with either α(1→4) units adjacent or α(1→6) linked branches could be resolved in a high-resolution 1H NMR experiment giving direct in situ information on the ratio of α(1→4) to α(1→6) units. This indicates that despite the relatively high MW (>1,000,000 Daltons) there is considerable segmental motion in the glycogen molecules giving long 1H T2 relaxation times. Magn Reson Med 44:201207, 2000. © 2000 Wiley-Liss, Inc.