Infantile haemangiomas (IHs) are the most common congenital vascular tumours of infancy. Propranolol has been demonstrated to be effective for IHs; however, the factors affecting its therapeutic effect remain unknown. We enrolled 169 infants with IHs of the head and neck region treated with oral propranolol at a dose of 2.0 mg/kg/day. We evaluated the therapeutic responses 6 months after treatment and the end of treatment, which were categorized into four grades. The type and location of the lesions and the infant age at treatment initiation were analysed. The clinical response rate (III + IV) was 91.72% at 6 months after treatment and 97.63% at the end of treatment. The average treatment duration was 9.99 (2–24) months. The group aged 4–6 months exhibited a greater therapeutic response rate (98.48%). The treatment duration was shorter (9.52 months) for mixed-type IHs. Better therapeutic responses were observed for IHs located around the parotid, periorbital, cheek, and neck regions and for multiple IH lesions. Our study indicated that propranolol is effective for IHs affecting the head and neck. The age at treatment initiation and the location of the lesions had a significant effect on the therapeutic response, whereas the lesion type might affect the treatment duration.