A significant proportion of men undergoing 'curative' radical prostatectomy (RP) for organ-confined prostate cancer relapse within 5 years. A number of adverse risk factors have been identified, but to date no adjuvant treatment as improved the outlook for these men. We proposed that these patients, despite small tumour burdens, may be immunosuppressed from their cancer, which may be amenable to immune modulation. We investigated their immune profile using sensitive functional cytokine assays, both pre- and post-surgery. In comparison with controls, RP patients expressed higher levels of both T helper type 1 (Th1) (interleukin (IL)-2 and tumour necrosis factor-alpha) and Th2 cytokines (IL-4, -5 and -10) with little change after removal of tumour. Further analysis based on known poor-prognostic factors indicated a trend to expression of higher levels of Th2 cytokines IL-4 and IL-5 in worse prognosis patients rather than the mixed Th1/2 found across the whole cohort. Persistently high levels of both Th1 and Th2 cytokines were detected in RP compared to control patients, despite the removal of relatively small tumour burdens. Cytokine expression studies may be useful as surrogate marker of potential disease progression, and could be used to identify patients who may benefit from immune modulation post-surgery.