Objective To explore the variation of serum galectin-3 and its correlation with ventricular remodeling in children with chronic cardiac failure (CHF). Methods Forty-five children with CHF were included and divided into cardiac function II group (n=10), III group (n=18), and IV group (n=17) according to the severity of CHF. The subjects were also divided into endocardial fibroelastosis (EFE) group (n=21) and dilated cardiomyopathy (DCM) group (n=24) according to primary disease. Thirty health children were included as control group. The level of serum galectin-3 was detected by ELISA. The level of serum NT-pro BNP was  measured by radio immunoassay. The index of ventricular remodeling was detected by ultrasonic cardiogram. The correlation of the level of serum galectin-3 with ventricular remodeling and the level of serum NT-pro BNP were analyzed. Results In 45 children (19 males and 26 females) with CHF, the mean age was 3.42±1.89 years. The levels of serum galectin-3 and NT-pro BNP were higher in cardiac function II group, III group, and IV group than those in control group (all P < 0.05) and significant differences in the levels also existed between cardiac function II group, III group, and IV group (P all < 0.05). The level of serum galectin-3 was not different between EFE group and DCM group (P > 0.05). Spearman rank correlation analysis showed that the level of serum galectin-3 was positively correlated with the left ventricular end diastolic diameter, the left ventricular mass, the left ventricular mass fraction, and the level of serum NT-pro BNP (all P < 0.05). Meanwhile the level of serum galectin-3 was negatively correlated with the left ventricular ejection fraction and the left ventricular fractional shortening (all P < 0.05). Conclusion Serum galectin-3 may be helpful in clinical diagnosis and assessment of CHF in children.