Levels of putrescrine, spermidine, and spermine in urine were determined by means of a sensitive ion-exchange chromatographic method in patients with advanced solid tumor malignancies, in patients with diseases other than cancer, and in normal control subjects. Elevation above 2 SDS of the normal mean were found in varying number of patients in each tumor category. For those malignancies studied that involved more than 20 patients, the greatest incidences of increased excretion were 66% for spermine in patients with colon carcinoma and 50% for putrescine and spermidine in patients with bronchogenic carcinoma. The highest levels and greatest frequency of elevated polyamine levels were found in patients with Burkitt's lymphoma, and changes in clinical tumor status associated with treatment appeared to correlate well with polyamine levels in this disease. Abnormal amounts of polyamines were also excreted by some patients with diseases other than cancer, indicating that increased polyamine excretion is not restricted or specific to the neoplastic state. It was also found that the levels of polyamines were apparently not affected by the intake of meat or the diet eaten, and remained in a rather narrow excretion range for any one individual at different time intervals. This study was carried out as part of a program to determine and evaluate biologic materials present in body fluids that may be used to follow and evaluate response or progression of neoplastic disease in patients during treatment regimens. The results suggest that abnormal urinary polyamine levels may be characteristic of neoplastic growth for some patients with malignant disease. Further studies are necessary to determine if these compounds may be helpful in assessing disease status for patients with such solid tumor malignancies as colon and bronchogenic carcinoma although their potential as useful "biologic markers" appears less promising than originally anticipated.