This study was conducted to determine the levels of Patients’ spiritual well-being (SWB) and self-care agency (SCA) of patients receiving chemotherapy with a port catheter. It was a correlational and observational study. Data were collected between December 2021 and March 2022. The sample was 88 people. Of the participants; 59.1% were women, 88.6% were married, 38.6% were primary school graduates, 47.7% were unemployed, and 51.1% had income equal to their expenses. Furthermore, 38.6% patients had breast cancer diagnosis and 52.3% did not have any chronic diseases. Both scale scores were affected by different variables and there was a positive correlation between SCA and SWB. Better SWB positively affected SCA. Patient age and duration after cancer diagnosis affected SCA and SWB. Notably, SCA and SWB levels of the patients may change with age and disease progression, and patients should also be monitored in this respect.