The outcome of patients with Thrombolysis in Myocardial Infarction (TIMI) trial grade 2 flow is worse than that of patients with TIMI grade 3 flow after thrombolytic therapy for acute myocardial infarction. It is unclear whether TIMI grade 2 flow represents incomplete recanalization of the culprit lesion or poor distal runoff. The Thrombolytic Trial of Eminase (anistreplase) in Acute Myocardial Infarction (TEAM)-2 and TEAM-3 were randomized trials comparing anistreplase with streptokinase (TEAM-2, n = 370) or with alteplase (tissue plasminogen activator) (TEAM-3, n = 325). We compared the minimal luminal diameter of the culprit lesion in patients with TIMI grade 2 flow with that in patients with TIMI grade 3 flow both 90 minutes (TEAM-2) and 1 day (TEAM-3) after thrombplysis. Patients with TIMI grade 2 flow had a lower residual luminal diameter in the culprit lesion than patients with TIMI grade 3 flow (TEAM-2, 0.58 ± 0.03 vs 0.79 ± 0.02 mm, p = 0.0001; TEAM-3, 0.88 ± 0.04 vs 1.17 ± 0.03 mm, p = 0.0001, for patients with TIMI grades 2 and 3 flow). Residual percent stenosis was correspondingly higher in patients with TIMI grade 2 flow. At the early angiogram, 66% of patients with TIMI grade 2 flow, but only 35% of those with TIMI grade 3 flow, had a minimal luminal diameter of 0.6 mm (positive predictive value 87%, negative predictive value 35%). Incomplete recanalization of the culprit lesion may thus be an important determinant of TIMI grade 2 flow after thrombolysis. Whether more complete thrombolysis or rescue angioplasty improves outcome in these patients deserves evaluation.