A meta-analysis of 11 studies (N=2124) investigating the impact of individual crisis intervention with medical patients yielded a significant, overall moderate effect size, d=0.44. The strongest effect of individual crisis intervention was on posttraumatic stress symptoms (d=0.57) and anxiety symptoms (d=0.52). Specific moderating factors, such as single versus multiple sessions, single versus multiple components of intervention, and level of interventionists' training, were also analyzed. In sum, the results support highly trained interventionists continuing to provide multi-session interventions in order to mitigate posttraumatic symptomatology following traumatic events.