Introduction: Serum amyloid-A (SAA) and protein carbonyl group are rigorously related with cardiovascular diseases (CVDs) as a sensitive marker of an acute inflammatory state and as an important index of oxidative stress, respectively. Moreover, diet is one of the main factors that can modify cardiovascular risks. Therefore, this study aimed to investigate the effects of Ramadan fasting on SAA and protein carbonyl group levels in patients with CVDs. Methods: Twenty-one patients (21 male; mean age 52±9 years old) with CVDs (coronary artery disease, cerebrovascular, or peripheral arterial diseases) were participated in this study. Biochemical parameters were measured in patients 2 days before and 2 days after Ramadan fasting. SAA levels were assessed using enzyme-linked immunosorbent assay and Cayman’s protein carbonyl colorimetric assay was provided for measuring protein carbonyl groups. Results: According to the findings of the study, post-Ramadan levels of inflammatory biomarker, SAA was decreased significantly in patients with CVDs in comparison with the baseline before-fasting values (16.84±8.20 vs. 24.40±6.72 μg/ml, P = 0.021). In addition, Ramadan fasting significantly reduced the levels of protein carbonyl group in patients as compared with those of baseline values (33.08±15.31 vs. 43.65±16.88 nmol/ml, P = 0.039). Conclusion: Ramadan fasting has impressive effects on modulating CVDs by decreasing inflammation and oxidative stress markers. However, to get a clear conclusion with more results, further investigation is warranted.