Objective To explore the effect of riboflavin on pathological myocardial hypertrophy and fibrosis in mice induced by transverse aortic constriction (TAC), and to preliminarily explore the relationship between this effect and short-chain acyl-CoA dehydrogenase (SCAD). Methods The C57BL/6 mice were randomly divided into 4 groups (n＝10): sham operation＋normal saline (NS) group (sham＋NS group), TAC＋NS group, sham＋riboflavin group, and TAC＋riboflavin group. The mice in each group were gavaged continuously for 5 weeks from 1 week before the operation to 4 weeks after the operation, and the gavage dose of riboflavin was 20 mg·kg^-1·d^-1. The systolic blood pressure of the tail artery of the mice in each group was detected at the 5^th week after the operation, the cardiac structure and function of the mice were evaluated by echocardiography, the heart weight/body weight ratio and heart weight/tibia length ratio were calculated, and the morphological changes of mice hearts were observed; the mRNA expression levels of cardiac hypertrophy markers in mice, the expression levels of mouse myocardial collagen, and the expression and enzymatic activity of SCAD were detected, and the contents of coenzyme flavin adenine dinucleotide (FAD) in myocardial SCAD, adenosine triphosphate (ATP) and free fatty acid were detected. Results Riboflavin could improve TAC surgery-induced pathological myocardial hypertrophy and fibrosis in mice; at the same time, it increased myocardial FAD content, SCAD protein and mRNA expression levels, SCAD enzyme activity, myocardial ATP content, and decreased myocardial free fatty acid content (all P＜0.01). Conclusion Riboflavin can improve pathological myocardial hypertrophy and fibrosis in mice. This effect may be achieved by increasing myocardial FAD content, promoting myocardial SCAD expression, enhancing myocardial fatty acid β oxidation, and improving myocardial energy metabolism.