The efficacy of Oridermyl(®) (acaricidal/antibiotic/antifungal/anti-inflammatory ointment) and Revolution(®) (selamectin spot-on) was compared in a blinded randomized study on 24 adult cats with otoacariasis. Twelve cats were treated once daily for 10 d with Oridermyl(®) and 12 cats were treated on Day 0 with Revolution(®). Otitis was assessed with cytological counts of mean number of bacteria and yeast on Days 0 and 10, and scored clinically every other day. All auricular secretions were removed for mite count on Day 10. On Day 0, cytological examination confirmed the presence of secondary bacterial (24/24) and fungal (21/24) infections. No live mites were observed otoscopically after Day 4 and in auricular secretions at Day 10 in both groups. On Day 10, secondary infections were resolved for all cats treated with Oridermyl(®) but were present in all cats treated with Revolution(®). Improvement in clinical signs of otitis over time was superior in the Oridermyl(®) group (P < 0.001).