The fracture behavior of a crumb rubber-filled elastomer was observed in optical micrographs. It was found that the failure started from the surface of the unfilled samples. The failure, however, started from a cavity around a crumb in the crumb-filled samples. This paper suggests that the failure mechanism in the crumbfilled elastomers (NR, NBR) was based on the microscopic observation of highly strained samples. This paper also considers the failure behavior of two-component systems: NR/NBR, SBR/NR, and NR/SBR.