Specimens of colon tissue were examined by 1H MRS (360 MHz) in order to determine the usefulness of rat colon (n = 44) as a model for human colon (n = 60), particularly for the characterization of preneoplastic lesions. Human tissue was characterized by 1H MRS as a precursor to in vivo studies. For both tissues, resonances from mobile lipids were not characteristic of pure mucosa, but correlated with the presence of submucosa. The mean intensities of the resonances at 3.2 and 3.4 ppm (assigned mainly to choline-containing compounds and taurine, respectively) of rat mucosa compared to those of human mucosa, and of rat tumours compared to human tumours, were not significantly different, while both resonances were significantly more intense in rat tumours compared to rat mucosa. The spectra of premalignant lesions in rat colon have features between those due to tumours and normal tissue. We conclude that rat colon is a useful model for human colon in 1H MR spectroscopic studies. MR spectra from human colon control tissue and tumours were classified with 100% accuracy using multivariate analysis.