Background: Docetaxel (DTX) is commonly used to treat metastatic prostate cancer, yet little data is available about the cost of a DTX chemotherapy episode of care (DEC) for treating mCRPC. This study analyzes DEC cost and health service utilization for men with mCRPC. Methods: We performed a claims-based analysis using Truven MarketScan and Medicare 5% sample data sets. Eligibility was required in all months of 2010 and ≥ 1 month of 2011, along with ≥ 1 2011 claim coded with prostate cancer and ≥ 1 DTX claim. Initial 2011 DECs required no DTX claim in the prior 12 months while subsequent DECs required a 60-day gap between DTX claims. DEC costs included all paid claims, except prescription drugs, from the 1st DTX claim to 30 days after the last DTX claim with early termination for death, insurance disenrollment or the end of a 24-month look-forward period. DTX drug costs were adjusted for 2011 generic DTX introduction while all other DEC costs were adjusted to 2015 using national average unit cost increase. Results: 155 commercially insured patients (COMM) and 281 Medicare patients (MDCR) were identified with 172 and 325 DECs, respectively. The average number of DTX cycles per DEC was 6.3 for COMM and 6.9 for MDCR, with 105 and 102 average days between the 1st and last infusion, respectively. The average DEC cost was $63,788 for COMM and $28,742 for MDCR with DTX drug costs contributing $13,169 (21%) and $2,588 (9%) per DEC, respectively. The average cost per DEC contributed by DTX-infusion days was $27,900 (44%) for COMM and $8,577 (30%) for MDCR. Non-DTX-infusion day costs per DEC included $10,838 (17%) for infused/injectable drugs for COMM and $7,074 (25%) for MDCR, along with $9,324 (15%) and $6,875 (24%) for inpatient admissions, respectively. 29% of COMM-DECs and 40% of MDCR-DECs had ≥ 1 inpatient admissions while 22% and 25% had ≥ 1 emergency room (ER) visit, respectively. 22% of COMM and 28% of MDCR inpatient costs and 15% of COMM and 33% of MDCR ER costs were chemotherapy related. Conclusions: Non-DTX drug costs including infusion day services, infused/injectable drugs administered on non-DTX days and inpatient admissions contributed the majority of DEC costs in COMM and MDCR mCRPC populations.