In this study, the effect of partial replacement of fine aggregate by crumb rubber (CR) on the fresh properties and stability of self-consolidating concrete was investigated. In total, eight mixtures with a water-to-binder ratio (0.4), a binder content 500 kg/m3, and varied percentages of crumb rubber (0-40% replacements by fine aggregate volume) were investigated for the effects on high-range water-reducer admixture (HRWRA) demand, flowability, passing ability, segregation resistance, and 28-day compressive strength. The results indicated that the fresh properties and strength of the tested mixtures generally decreased as the crumb rubber increased. However, the tested mixtures showed acceptable fresh and hardened performance of up to 15% replacement of CR. Meanwhile, using CR replacement higher than 20% resulted in a significant decrease in the fresh properties and 28-day compressive strength. The results also showed that owing to the low-density of the used rubber (0.95 gm/cm3), the mixtures with CR replacement more than 15% clearly suffered from unstable suspension of CR particles.