OBJECTIVES:  Study aimed to understand the treatment algorithm of HR+/HER2- post menopausal advanced/metastatic breast cancer in Turkey and to calculate the direct treatment cost of the disease based on this algorithm. METHODS:  Delphi panel method was used. In this regard, a questionnaire form about the epidemiology, diagnosis, treatment, monitoring, palliative care and adverse events of HR+/HER2- postmenopausal advanced/metastatic breast cancer were prepared in order to identify the number of patients, type and frequency of healthcare resources used. The form was filled in by five experts from public and private tertiary care institutions based on their daily practice. Answers were aggregated and a consensus form indicating the treatment algorithm was formed. The resources were priced by using the official price lists of the Social Security Institution and the Ministry of Health. RESULTS: Study results revealed the treatment algorithm and medical resources used in diagnosis, 1^st/2^nd/3^rd and 4^th lines of treatment, monitoring, palliative care and adverse events. Distribution of HR+/HER2- post menopausal metastatic breast cancer patients among 1^st, 2^nd, 3^rd, and 4th line treatments were 50%, 25%, 17%, 8% and rates of transmission in 1 year from 1^st to 2^nd line, from 2^nd to 3^rd and from 3^rd to 4^th were 32%, 56%, 72% respectively. Diagnosis cost per patient was estimated as $265.95 and the annual costs of 1^st/2^nd/3^rd and 4^th lines of treatment per patient were estimated as $1,285.71, $1.591,89, $4,359.55, and $1,973.48 respectively. The annual monitoring costs of 1^st/2^nd/3^rd and 4^th lines of treatment per patient were estimated as $901.31, $1,036.37, $949,24, $1,018.07 respectively. CONCLUSIONS:  Study revealed that there are different treatment approaches for HR+/HER2- post menopausal advanced/metastatic breast cancer treatment in Turkey. Total treatment costs to public payer have been calculated, taking into account all direct medical costs including adverse events, revealing differences between treatment lines.