Patients with Acute Coronary Syndrome (ACS) are at risk of experiencing problems in various aspects of life. Changes in spiritual conditions are one of the problems that often occur, especially spiritual well-being. Existential well-being (EWB) and religious well-being (RWB) are specific parts of spiritual well-being that will be analyzed in this study. The research design used is descriptive with a cross-sectional approach. The study population was patients who experienced Acute Coronary Syndrome and were treated in the cardiac intensive unit with a total of 84 patients who were taken using a non-probability sampling technique with a purposive sampling method. The instrument used is the Indonesian version of the Spiritual Well-Being Scale (SWBS) questionnaire and has received permission from the original owners Ellison and Paloutzian by paying for the copyright. The results showed that the level of religious well-being (RWB) and existential (EWB) was in the high category with 86.9% and 71.4% respectively. There were no respondents who had a low level of religious or existential spiritual well-being. Health service providers are expected to be able to assess the spiritual well-being of ACS patients so that spiritual problems can be detected and efforts to treat them as early as possible.