The first Canadian Symposia on Catalysis was successfully held in 1965. Since then, the series of meetings has been held biannually. The contributed papers increased from 15 in 1965 to more than 100. Participants expand from three countries in 1965 to every continent for the present. The evolution of the Canadian Symposium on Catalysis will be seen from a local forum with limited size to an international meeting of significant size.