Pope Paul VI created him cardinal priest of Nostra Signora de La Salette in the consistory of April 28, 1969. Scherer was one of the cardinal electors who participated in the conclaves of August and October 1978, which selected Popes John Paul I and John Paul II respectively. In January 1980, he was stabbed and robbed by unknown assailants, who left him in a ditch outside Porto Alegre when he could not meet their demands for more money. After thirty-four years of service, the Cardinal resigned as archbishop on August 29, 1981.