Over a period of three months in 1985, paramyxovirus type 1 infection was demonstrated for the first time in Canada, in six flocks of pigeons in Ontario, Alberta, and British Columbia. The paramyxovirus type 1 isolates did not cause clinical disease when serially passaged four times in four-to six-week-old chickens, and isolates were classified as lentogenic before and after such serial passage. Further cases of paramyxovirus type 1 clinical disease have not been reported since the last of these six outbreaks in August 1985.