Elevated fibrinogen (Fg) level is a known risk factor for ischemic stroke. There are few clinical trials on oral fibrinogen-depleting therapies for secondary ischemic stroke prevention. We aimed to assess the effects of one-year therapy with oral lumbrokinase enteric-coated capsules on secondary ischemic stroke prevention. This is a multicenter, randomized, parallel group and controlled study that began treatment in hospitalized patients with ischemic stroke and continued for 12 months. Patients were randomized to either the control group that received the standard stroke treatment or the fibrinogen-depleting group that received the standard stroke treatment plus enteric-coated lumbrokinase capsules. The NIH Stroke Scale scores (NIHSSs) and plasma Fg level were recorded. The carotid artery intima-media thickness (IMT) and status of plaques were examined through carotid ultrasound examination. Primary outcomes included all-cause mortality, any event of recurrent ischemic stroke/transient ischemic attack (TIA), hemorrhagic stroke, myocardial infarction and angina, and other noncerebral ischemia or hemorrhage. Kaplan-Meier survival analysis and the Long-rank test were used to compare total vascular end point incidence between the two groups. Comparison of median values between two groups was done by the Student t test, one-way analysis of variance (ANOVA), or non-parametric rank sum test. A total of 310 patients were enrolled, 192 patients in the treatment group and 118 patients in the control group. Compared to the control group, the treatment group showed favorable outcomes in the Fg level, carotid IMT, the detection rate of vulnerable plaques, the volume of carotid plaques, NIHSS scores, and incidence of total vascular (6.78% and 2.08%, respectively) and cerebral vascular events (5.93% and 1.04%, respectively) (P < 0.05). In the treatment group, the volume of carotid plaques was significantly related to the carotid IMT, the plaque diameter, width and number (P = 0.000, 0.000, 0.000, 0.022; F = 13.51, 2.52, 11.33, -3.29, but there was a weak correlation with the Fg level (P = 0.056). After 1-year therapy, the incidence of overall vascular end points was reduced by 4.7%. Long-term oral fibrinogen-depleting therapy may be beneficial for secondary ischemic stroke prevention.