A number of theories have proposed possible mechanisms that may explain the high rates of comorbidity between posttraumatic stress disorder (PTSD) and persistent pain; however, there has been limited research investigating these factors.The present study sought to prospectively examine whether catastrophizing predicted the development of PTSD symptoms and persistent pain following physical injury.Participants (N=208) completed measures of PTSD symptomatology, pain intensity and catastrophizing during hospitalization following severe injury, and 3 and 12 months postinjury. Cross-lagged path analysis explored the longitudinal relationship between these variables.Acute catastrophizing significantly predicted PTSD symptoms but not pain intensity 3 months postinjury. In turn, 3-month catastrophizing predicted pain intensity, but not PTSD symptoms 12 months postinjury. Indirect relations were also found between acute catastrophizing and 12-month PTSD symptoms and pain intensity. Relations were mediated via 3-month PTSD symptoms and 3-month catastrophizing, respectively. Acute symptoms did not predict 3-month catastrophizing and catastrophizing did not fully account for the relationship between PTSD symptoms and pain intensity.Findings partially support theories that propose a role for catastrophizing processes in understanding vulnerability to pain and posttrauma symptomatology and, thus, a possible mechanism for comorbidity between these conditions.