OBJECTIVE: • To evaluate the cost-effectiveness of early prostate cancer detection with the Beckman Coulter Prostate Health Index (phi) (not currently available in the USA) adding to the serum prostate-specific antigen (PSA) test compared with the PSA test alone from the US societal perspective. PATIENTS AND METHODS: • Phi was developed as a combination of PSA, free PSA, and a PSA precursor form [-2]proPSA to calculate the probability of prostate cancer and was used as an aid in distinguishing prostate cancer from benign prostatic conditions for men with a borderline PSA test (e.g. PSA 2-10 ng/mL or 4-10 ng/mL) and non-suspicious digital rectal examination. • We constructed a Markov model with probabilistic sensitivity analysis to estimate expected costs and utilities of prostate cancer detection and consequent treatment for the annual prostate cancer screening in the male population aged 50-75 years old. • The transition probabilities, health state utilities and prostate cancer treatment costs were derived from the published literature. The diagnostic performance of phi was obtained from a multi-centre study. Diagnostic related costs were obtained from the 2009 Medicare Fee Schedule. • Cost-effectiveness was compared between the strategies of PSA test alone and PSA plus phi under two PSA thresholds (≥2 ng/mL and ≥4 ng/mL) to recommend a prostate biopsy. RESULTS: • Over 25 annual screening cycles, the strategy of PSA plus phi dominated the PSA-only strategy using both thresholds of PSA ≥2 ng/mL and PSA ≥4 ng/mL, and was estimated to save $1199 or $443, with an expected gain of 0.08 or 0.03 quality adjusted life years, respectively. • The probabilities of PSA plus phi being cost effective were approximately 77-70% or 78-71% at a range of $0-$200,000 willingness to pay using PSA thresholds ≥2 ng/mL and ≥4 ng/mL, respectively. CONCLUSION: • The strategy PSA plus phi may be an important strategy for prostate cancer detection at both thresholds of PSA ≥2 ng/mL and PSA ≥4 ng/mL to recommend a prostate biopsy compared with using PSA alone.