The polyamines, spermidine and spermine, and the precursor diamine, putrescine, may have an important role in control of cellular growth because of their interaction with nucleic acid structure, function, and synthesis. We have developed a quantitative gas-chromatographic procedure for measuring polyamines and have measured their urinary excretion by cancer patients and noncancerous patients. Marked variations in values obtained during therapy and in response to some other variables are described. Both hydrolyzed and nonhydrolyzed urine samples have been examined, in order to quantitate both total and free polyamine and putrescine excretions. The potential clinical importance of these studies and the application of other instrumentation such as mass spectroscopy to improve the specificity and sensitivity of this method are discussed.