Hexamethylol melamine (HMM) was characterized by Fourier transform infrared (FTIR) spectroscopy. The optimum dose of HMM in the presence of a sulfur accelerator in a natural rubber (NR)-filled compound was determined. The cure rate and kinetics of crosslink formation indicate that HMM enhances the first-order rate of vulcanization in an NR compound. The results reveal good mechanical properties of an HMM-based NR carbon black-filled vulcanizate.