Probably 15 out of 18 cardinals participated in the election:

The following cardinals did not participate in the conclave:

At least five cardinals did not participate in this election.

All sixty-two cardinals participated in the conclave.

Ten cardinals (over 1/3 of the whole Sacred College) did not participate in this conclave:

Two cardinals and eight bishops participated in parts or all of the two week meeting, as well as many priests, religious and seminarians from around the world.

Initially only 27 cardinals participated.

Eight cardinals did not participate in this conclave:

Four cardinals, all created by Alexander VII, did not participate in this conclave:

Paul VI revolutionized papal elections by ordering that only cardinals below the age of eighty might participate in future conclaves.