Onychocola canadensis can cause onychomycosis of the toenails. Thirty-two cases have been described up to now. We report on the isolation of Onychocola canadensis from four patients with onychomycosis who acquired their infection in Belgium. Direct examination was positive. Onychocola canadensis was isolated in pure culture. According to the previously published cases, the patients affected were elderly and the preferential site of infection was the big toenail. In contrast to previous reports, we found a predominance in males. Treatment was started in all patients. Two out of the three patients about whom information was available, did not improve after treatment