Introduction: Acute Coronary Syndrome(ACS) is one of the most common cardiovascular diseases. Proper diet plays an important role in disease prevention and control. Adherence to the diet in acute coronary syndrome (ACS) patients has a significant effect in preventing re-hospitalization and reducing the complications of the disease. Objective: This study was conducted in order to determine the effect of a family-oriented self-care program based on home visits on diet adherence of 1400 discharged acute coronary syndrome patients. Materials and Methods: In this semi-experimental study that was conducted in 2021-22, 72 people with ACS were randomly divided into two test and control groups (36 people in each group). For the control group, routine interventions and Family-centered self-care was performed for the test group. Data collection tools were demographic profile questionnaire and diet adherence questionnaire. The data were analyzed using descriptive and inferential statistics with a significance level of P<0.05 by SPSS software. Reslts: The average score of adherence to the diet before the intervention in the two test and control groups was equal to 5.37 ± 2.09 and It was 5.12 ± 1.1 and there was no significant difference (P>0.05). The average score immediately after the intervention in the two test and control groups, respectively, equals 6.74±1.22 and 0.16, 5.08±1.5 months after the intervention, 7.23±1.09 and 0.90± It was 5.12, which was significantly higher in the test group than the control group (P<0.05). Conclusion: family-oriented self-care in patients with acute coronary syndrome is effective on adherence to the diet of these patients. Therefore, it is recommended to use this educational method as one of the effective and non-pharmacological methods for people with ACS in medical centers and at home to improve the quality of life of these patients.