Ethylene propylene diene rubber (EPDM) was brominated. The curing behavior and tensile properties of the brominated EPDM (BEPDM) were investigated using a typical sulfur curing formulation. The brominated EPDM was observed to cure with a shorter cure induction time than the unbrominated one. The activation energies (Ea) of curing for EPDM and brominated EPDM were found to be approximately 145 kJ/mol and 58 kJ/mol, respectively. Analysis of curing behavior with individual curatives and stress-strain measurements indicates that these significant improvements could be attributed to the role of bromine as a more efficient crosslinking site, forming C—O—C crosslinks. In addition, the bromine also seems to increase the solubility of sulfur in the rubber, promoting sulfur crosslinks which are apparently not observed with the unbrominated EPDM. Consequently, the BEPDM displayed significantly higher tensile strength than the unbrominated one.