In this study, the safety and efficacy of an spot on formulation composed of Fluralaner (40mg/kg)and Moxidectin (2mg/kg) against internal and external parasites was evaluated in Korean cats. The product was developed as a topical use in cats to prevent or control internal and external parasites including ticks, fleas, gastrointestinal parasites, ear mite and heartworm. As a result of the study, targeted for total 30 cats from 8 Korean animal hospitals, this combination of Fluralaner and Moxidectin was found to be very safe in cats, and its effectiveness against external parasites (ticks, fleas, and ear mites) was fully verified. In addition, As the animals exposed in the infective circumstances of heartworm and gastrointestinal parasites were remained negative during the study period of 12 weeks after treatment of test drug, it was determined that this product had a potential preventive effect against the heartworms and gastrointestinal parasites.