In a previous study, women with posttraumatic stress disorder (PTSD) had greater objective sleep disturbance than those without PTSD. In a separate previous study, women with PTSD were also found to have lower baroreceptor sensitivity (BRS), an index of blood pressure regulation. In the present study, the authors concurrently assessed BRS and objective sleep by diagnostic status. A comparison of 32 women with PTSD with 21 women without PTSD revealed an interaction between BRS and sleep efficiency, wake after sleep onset percentage, and sleep fragmentation. Lower BRS was associated with poorer sleep in women with PTSD, but not in those without. Future research should investigate causal relationships between sleep and blood pressure regulation in those with PTSD.