Abstract Purpose Cost evaluation is becoming mandatory to support healthcare sustainability and optimize the decision-making process. This topic is a challenge, especially for complex and rapidly evolving treatment modalities such as radiotherapy (RT). The aim of the present study was to investigate the cost of RT in the last month of life of patients in an Italian cancer center. Methods This was a retrospective study on a cancer population (N= 160) who underwent RT or only an RT planning simulation in an end of life (EOL) setting. The cost of RT procedures performed on patients was collected according to treatment status, care setting, and RT technique used. Costs were valued according to the sum of reimbursements relating to all procedures performed and assessed from the perspective of the National Health System. Results The total cost of RT in the last month of life was €244,774, with an average cost per patient of €1530. Around 7.7% and 30.3% of the total cost was associated with patients who never started RT or who discontinued RT, respectively, while the remaining 62.0% referred to patients who completed treatment. Costs associated with outpatient and inpatient settings represented 54.3% and 38.6% of the total cost, respectively. The higher average cost per patient for the never-started and discontinued groups was correlated with patients who had a poor ECOG Performance Status. Conclusion Improved prognostic accuracy and a better integration between radiotherapy and palliative care units could be a key to a better use of resources and to a reduction in the cost of EOL RT.