To determine whether troponin I (cTnI) and right ventricular (RV) dysfunction predict adverse in-hospital outcomes in patients admitted to the Emergency Department (ED) with definite nonmassive pulmonary embolism (PE) independent of and in addition to a recently validated clinical prognostic risk score. From a pool of 168 patients with suspected PE, 89 had nonmassive PE confirmed by spiral lung angio-computed tomography. By the clinical prognostic score, in our study sample, 14% had very low risk; 17% had low risk, 20% had intermediate risk, whereas high risk and very high risk were identified in 29 and 20%, respectively. Prevalence of elevated cTnI (>0.1 microg/L, 57%) at admission was comparable among patients grouped by clinical prognostic score (P = NS); echocardiographic RV dysfunction (54%) was more prevalent with intermediate or high clinical risk score (P < 0.02). Increased cTnI predicted primary end-point (development of hemodynamic instability, overall 33 cases, 37%) independent of and in addition to the clinical risk class and RV dysfunction (P < 0.01 for interaction). Fatal events (12 cases, 14%, 5 definite, 7 possible PE-related) were predicted by higher clinical risk score (P < 0.05). In patients with nonmassive central PE admitted to the ED, increased cTnI contributed to identifying those with increased risk of development of hemodynamic instability independent of and in addition to a validated clinically based risk score.