Background No single theory can explain the characteristics of infantile hemangioma (IH), but the emergence of new biomarkers will help to discover a general mechanism in its pathogenesis. Objective To evaluate serum level of galectin-3 (gal-3) in patients with IH and its possible role in the pathogenesis during proliferative and involuting phases. Patients and methods This case–control study included 60 patients with IH as group 1 (G1). They were subdivided into 30 patients with age ranged from 3 to 12 months (proliferative phase, G1A) and 30 patients with age ranged from more than 12 to 24 months (involuting phase, G1B). In addition, 20 age-matched and sex-matched healthy participants who served as a control group (G2) were included. The diagnosis was based on clinical bases and ultrasonic examination. Assessment of serum level of gal-3 was done by enzyme-linked immunosorbent assay kits in all studied groups and was correlated with clinical findings of IH. Results Serum gal-3 levels were significantly higher in the patient group (G1) than controls (G2) (P=0.001). Serum gal-3 levels were significantly higher in G1B compared with G1A and controls (G2B) (P