Aims: Right ventricular (RV) dysfunction is a frequent consequence of pulmonary embolism (PE) and a marker of increased risk. However, current qualitative methods assessing RV function are imprecise. We sought to determine whether RV strain analysis would have clinical utility in patients with PE compared with normal controls. Methods and results: We compared 75 acute PE subjects (mean age 54 ± 16) with 30 normal controls (mean age 50 ± 15). Regional RV longitudinal strain was assessed using offline speckle tracking software to obtain strain and strain rate data from the basal, mid, and apical free wall and septum. Global RV free wall and septal strain was significantly reduced in PE subjects (-14.17 (±5.96) vs -24.92 (±4.16), P < 0.0001; -14.99 (±5.55) vs -18.54 (±7.34), P = 0.0082). Regional RV strain was markedly reduced in PE subjects in all regions of the free wall and in the mid and basal septum (P < 0.05). Strain rates of PE subjects were significantly reduced in all segments of the RV free wall (P < 0.05). In 36 PE subjects with regional RV dysfunction ("McConnell sign"), strain in the apical free wall was significantly reduced in comparison to those without (-10.08 vs -13.51; P = 0.0420), in parallel with higher RV:LV ratios (1.30, ±1.01 vs 0.78, ±0.16; P = 0.0035) and lower RV fractional area change (32.06, ±14.42 vs 42.52, ±11.61; P = 0.0021). Conclusions: Regional RV longitudinal strain is altered in the free wall and mid and basal septum in subjects with acute PE. Strain rates are only reduced in the RV free wall. (Echocardiography 2012;29:464-470) © 2012, Wiley Periodicals, Inc.