The objective is to examine the cost-utility of sipuleucel-T immunotherapy in asymptomatic or minimally symptomatic castration-resistant prostate cancer patients. The addition of sipuleucel-T immunotherapy to standard treatment led to a gain of 0.37 quality-adjusted life-year (QALY) at an additional cost of US$104,536. The incremental cost-utility ratio was US$283,000 per QALY saved. Threshold sensitivity analyses indicated that a price reduction of at least 53%, or application in a group of patients resulting in the relative reduction in the mortality rate of at least 39%, ought to augment the economic value of this regimen. Sipuleucel-T immunotherapy treatment at the current price with 96.5% certainty is not cost-effective. The specific group of patients who will benefit more from the treatment should be revealed and treated, or the cost of the vaccine should be lowered significantly to increase its economic value. Accounting for crossover treatment in control patients improves sipuleucel-T's value (US$132,000 per QALY saved) although further investigation is necessary.