OBJECTIVES: The objective of the study is to determine the cost of illness associated with metastatic castration-resistant prostate cancer (mCRPC) from the perspective of payer [Social Security Institution (SSI)] in Turkey. METHODS: Cost of illness methodology was used by focusing only on direct costs. Delphi technique was applied to determine the type and the amount of resources used based on physicians’ clinical assessment. Epidemiology, diagnosis, treatment of symptoms and skeletal related events (SRE), side effects, follow-up visits, hospital admissions were questioned during an expert panel which gathered physicians from different specialties. Unit costs of resources used in outpatient and inpatient were obtained from official lists of SSI and total costs were calculated. Calculations were made in TRY and converted to EUR using the current currency (May 2016). RESULTS: The cost of the interventions was calculated as €2,002.39 for docetaxel, €7,591.71 for cabazitaxel, €18,503.11 for abirateron, €5,149.46 for lutetium and €3,431.29 for strontium-89/samarium-153. The expenses of skeletal related events (SRE) included in the cost calculation were found as €2,311.17 for pathological bone fracture, €6,734.28 for bone surgery, €1,197.09 for external beam radiotheraphy and €8,161.44 for spinal cord compression. Side effects included in the calculations were determined as nausea-vomiting, diarrhea, anemia, hypokalemia, thrombocytopenia, neutropenia, and febrile neutropenia. Annual mean following cost per patient was found as €218.44. Mean intervention cost was calculated as €18,927.57. Annual mean cost for SREs per patient was found as €5,679.16 and annual mean cost for side effects per patient was €1,179.88. CONCLUSIONS: Monthly mean mCRPC cost per patient is calculated as €2,167.09 from the perspective of SSI. In Turkey, number of patients with mCRPC is estimated as 300 and total cost is calculated as €650,127/month. This amount is the 0,022% of the expected monthly average health expenditure of Turkey in 2016.