Two adult sibling red-handed tamarins ( Saguinus midas) presented with weight loss and multifocal skin masses. A skin biopsy revealed pyogranulomatous dermatitis with intrafollicular Demodex sp. mites. Subsequent skin scrapes confirmed the presence of live mites within lesions. Initial treatment with topical and oral ivermectin was unsuccessful, and lesions continued to progress. A single dose of fluralaner (Bravecto®, Merck Animal Health, Kenilworth, New Jersey, 07033, USA; 28.125 mg po) was administered to each animal approximately 5 mo after initial presentation. Lesions resolved over the next 3 mo, and all follow-up skin scrapes were negative for both animals. No adverse effects were noted. A single oral administration of fluralaner at 30-35 mg/kg appears adequate and safe for the treatment of generalized demodicosis in red-handed tamarins.