Families with treated patients suffering from Acute Coronary Syndrome in the Intensive Room, mostly experience anxiety and symptoms of depression, fatigue and poor quality sleep. The reality of the impact of anxiety on the patient's family member is causing problems with the physical and mental health of the patient. The purpose of this study was to determine the factors that influence family anxiety of acute coronary syndrome patients. The method used is correlative analytic cross sectional study approach with a sample of 60 respondents. Family anxiety measurements used the Hamilton Rating Scale for Anxiety (HRS-A) questionnaire. The results showed that there were effects of age, length of stay of patients, sex, education level, experience on family anxiety with statistical values (0.000; P<0.05). Linear regression analysis shows the results that female gender is the most influential variable positively on anxiety scores (β=1.7). The conclusions of this study are gender, length of stay of patients and family experience, positively and significantly influence the increase in family anxiety scores.