The cure of adult solid tumors with chemotherapy remains illusive. However, useful palliation and survival prolongation are possible in a number of cancers. Chemotherapy can have major side effects, and a balance must be struck between the likely benefits and expected toxic effects and inconveniences of the therapy to the patient. The biology of prostate cancer is extremely variable, ranging from a condition causing little or no inconvenience, to a progressive, debilitating, rapidly fatal illness. For this latter group of patients, particularly those resistant or unresponsive to hormone therapy, chemotherapy is a therapeutic modality with potential for halting or reversing the disease process. Considerable effort has been expended in the last 15 years searching for useful drugs. The patterns of metastatic disease in prostate cancer make the assessment of response exceedingly difficult, and the results of different studies, showing widely divergent results, difficult to interpret. When strictly objective criteria are employed, very few drugs show worthwhile activity, with only mitomycin-C, doxorubicin, and cis-platinum exhibiting 20% plus response rates. Further effort is needed to identify useful drugs, but consideration must also be given to the effect of therapy on the patient's quality, as well as duration, of survival.