We describe methodology for the diagnosis of human cancer, at high levels of accuracy, sensitivity, and specificity, by 1H NMR of tissue biopsies. This method is made robust and accurate by careful specimen preparation, and by multivariate analysis of spectral data. Examples are presented for the diagnosis of cancer of the prostate gland and the ovary. The potential for use of these methods noninvasively, in vivo, is shown to be very positive.