Infantile hemangiomas (IH) undergo rapid growth during early infancy followed by gradual involution. After involution, a part of IH remain as residual lesions. Since 2008, oral propranolol has been widely used in the treatment of IH. However, long‐term outcome of IH treated with propranolol remains unknown. This study aimed to investigate the sequelae of IH treated with propranolol. In this study, propranolol was given at a dose of 2 mg/kg per day at the age of 3.8 ± 2.5 months and follow‐up visits were arranged to continue at least through the age of 4 years. Types of sequela were recorded and classified as four degrees (“none”, “minimal”, “significant” and “severe” at last visit), then subsequent therapy was evaluated with the help of magnetic resonance imaging (MRI). A total of 73 patients with complete follow up were enrolled in the study. The most common types of sequela were telangiectasia, fibrofatty tissue and erythema. Significant and severe sequelae were observed in 72.4% of treated IH; superficial IH led to more but not significantly significant and severe sequelae than mixed IH (P > 0.05). Despite propranolol treatment, surgery was still needed in 37.5% of IH at a mean age of 70.3 months, and for the main reason of surgery, fibrofatty or hemangioma residua, MRI was useful for us to choose an appropriate surgical procedure.