Sepsis is a frequently lethal state, commonly associated with left ventricular (LV) dysfunction. Right ventricular (RV) dysfunction in sepsis is less well understood.In septic patients, how common is right ventricular dysfunction, and is it associated with worse outcomes?We measured echocardiographic parameters on critically ill patients with severe sepsis or septic shock within the first 24 hours of ICU admission. We defined RV dysfunction as fractional area change (FAC) < 35% or tricuspid annulus systolic plane excursion (TAPSE) < 1.6 cm. We defined LV systolic dysfunction as ejection fraction (EF) < 45% or longitudinal strain > -19%. Using logistic regression, we assessed the relationship between 28-day mortality and presence of RV dysfunction and LV systolic dysfunction, controlling for receipt of vasopressors, receipt of fluid, mechanical ventilation, and the acute physiology and chronic health evaluation (APACHE II) score.We studied 393 patients. RV and LV dysfunction were common (48% and 63%, respectively). Mean echocardiographic values were: RV end-diastolic area: 22.4 ± 7.0 cm2, RV end-systolic area: 14.2 ± 6.0 cm2, RV FAC 38 ± 11%, TAPSE 1.8 ± .06 cm, RV longitudinal strain -15.3 ± 6.5%, LV EF 60 ± 14%, LV longitudinal strain -16.5 ± 6.0%. Patients with right ventricular dysfunction had higher 28-day mortality (31% vs 16%, p = 0.001). In our multivariable regression model, RV dysfunction was associated with increased mortality (OR 3.4, CI 1.7-6.8 p = 0.001), while LV systolic dysfunction was not (OR 0.63, CI 0.3 -1.2 p = 0.32) INTERPRETATION: Right ventricular dysfunction is present in nearly half of studied septic patients and is associated with over threefold higher 28-day mortality.