De Mattia cut growth, an important fatigue test, of a number of crosslinked elastomers based on terpolymers of isobutylene, p-methylstyrene, and p-bromomethylstyrene brominated isobutylene paramethylstyrene copolymers (BIMS), butadiene rubber (BR), and blends of BR and natural rubber (NR) has been studied. In these compounds the carbon black level and the cure state are varied. We attempt to relate this fatigue performance to bulk mechanical properties (strain at break, epsilon(b), and strain energy density, U) and network structural parameters (contour length, L-c,L- and root-mean-square end-to-end distance, [r], of network molecular chains).