Despite efforts by civil defense authorities, levels of households' preparedness to emergencies remain insufficient in many countries. Engaging the public in preparedness behavior is a challenge worldwide. The purpose of this study was to explore the efficacy of psychological intervention in promoting preparedness behavior to armed conflicts in Israel.A randomized controlled trial (N = 381) with two control groups and three intervention groups was used. The psychological interventions studied were elevated threat perception, external reward, and manipulation of a cognitive cluster related to preparedness.The results of the analysis suggest a significant effect of intervention on the increase of reported preparedness (F4,375 = 4.511, P = 0.001). The effect is attributed to the intervention group in which external reward was offered. Participants in this group were about two times more likely to report greater levels of preparedness compared to the control group (RR = 1.855; 95% CI: 1.065, 3.233).The findings suggest that preparedness behavior can be promoted through external incentives. These are presumably effective motivators because they encourage preparedness while allowing subjects to retain their denial as an adaptive coping mechanism. Innovative thinking is required to overcome the psychological barriers associated with public reluctance to engage in preparedness. (Disaster Med Public Health Preparedness. 2018;13:713-723).