Purpose: To report a case of frosted branch angiitis associated with COVID-19-related multisystem inflammatory syndrome in children (MIS-C).Case summary: An 8-year-old boy was referred to the ophthalmology clinic with decreased visual acuity in his right eye. The initial best-corrected visual acuity (BCVA) was 20/63 in the right eye and 20/32 in the left eye. Upon fundus examination, bilateral frosted branch-like vascular sheathing and retinal hemorrhage were observed. Optical coherence tomography (OCT) demonstrated macular edema. Fluorescein angiography revealed late staining and leakage of affected retinal vessels. The patient exhibited persistent fever, rash, and gastrointestinal symptoms, accompanied by an increase in inflammatory markers in laboratory tests. Testing for SARS-CoV-2 immunoglobulin G (IgG) was positive, although there was no evidence of any other autoimmune diseases or viral infections. The patient was diagnosed with frosted branch angiitis associated with MIS-C. Treatment included systemic steroids and 1% prednisolone eye drops. After 2 weeks, the BCVA improved to 20/20 in both eyes, and all clinical signs resolved without recurrence. Conclusions In patients with frosted branch angiitis without any other apparent cause, the possibility of MIS-C should be considered. Testing for COVID-19 infection is recommended.