Infantile hemangiomas (IH) are common benign tumors of infancy. Most IH involute, either spontaneously, or secondary to pharmacological treatment with systemic propranolol. Propranolol treatment mostly leads to regression of hemangiomas with satisfactory aesthetic results, but unfortunately not in all cases. To assess the safety and efficacy of long pulsed Nd:YAG 1064 nm laser in treating patients with residual infantile hemangioma after systemic propranolol treatment. This is an open-label prospective cohort study. 30 patients with focal residual IH that had sub-optimal responses to systemic propranolol treatment were enrolled in the study. The patients were treated with 1 to 3 sessions with long pulsed Nd:YAG 1064 nm laser. The maximal response of the IH was assessed using a 4-point scale evaluation scale system. Of the 30 patients enrolled, 18 patients exhibited a great response (> 76% improvement), 10 patients had a good response (> 51–75% improvement), while only 2 patients showed a moderate response (< 50% improvement) to the treatment. No patients had an unsatisfactory response. No serious side effects were observed, and only minor side effects were reported. The treatment with long pulsed Nd:YAG 1064 nm laser for residual IH, which were resistant to systemic propranolol treatment, is safe and effective. Thus, we suggest its use as a second-line treatment for patients with sub-optimal aesthetic results following systemic propranolol.