Women are two to three times more likely to develop posttraumatic stress disorder (PTSD) compared with men after exposure to a major trauma, and PTSD is associated with increased risk for cardiovascular disease in later life. The underlying mechanisms are unclear, but alterations in cardiac function may be involved. We hypothesized that women with PTSD have reduced left ventricular (LV) diastolic function. We studied 14 women with PTSD (PTSD group) and 14 women without PTSD (controls) using echocardiography Doppler to evaluate LV diastolic function, including peak velocities (E and A waves) in transmitral flow; diastolic, atrial kick, and systolic waveform velocities (e′, a′, and s′) in tissue Doppler; the ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e′); and velocity of propagation ( V_p) . Baseline characteristics including age, body size, blood pressure, and heart rate were not significantly different between the two groups. Compared with the control group, women with PTSD showed greater E/e′ (controls vs. PTSD group: 7.0 ± 1.3 vs. 9.1 ± 1.3, P = 0.002) and smaller V_p (controls vs. PTSD group: 63.7 ± 11.3 vs. 47.5 ± 6.9 cm/s, P = 0.003). These results suggest that women with PTSD have reduced LV diastolic function, which may contribute, at least in part, to the increased risk of cardiovascular disease later in life.