The chemorheology of cross-linked polyethylene disulfide, polyethylene tetrasulfide, and mixtures of these polymers with elemental sulfur is investigated. It is shown that stress decay in the disulfide polymer occurs by scission of the small quantities of higher poly­sulfide linkages present in the network. It is also shown that elemental sulfur decreases the chemical relaxation time in cross-linked polyethylene disulfide in a predictable manner.