In patients receiving coronary stents treated with aspirin and coumadin, the peak incidence of stent thrombosis occurs on the fifth and sixth days following the implantation procedure. Little is known about the timing of stent thrombosis in patients treated with aspirin and ticlopidine. We compared the timing of coronary stent thrombosis in patients treated with ticlopidine and aspirin with the timing in those receiving coumadin and aspirin. A retrospective databank analysis was performed and 39 patients were identified who experienced stent thrombosis after successful coronary stent implantation. Of these, 21 had been treated with ticlopidine and aspirin and 18 with coumadin and aspirin therapy. The median time from stent implantation to stent thrombosis in the ticlopidine and aspirin group was 12 hours (interquartile range 6 to 72 hours) compared with 4 days in the coumadin and aspirin group (interquartile range 21 to 68 hours) (p <0.0001). There was no significant difference between the timing of stent thrombosis in patients treated with abciximab in addition to ticlopidine and aspirin (median 17 hours, interquartile range 6 to 29) versus ticlopidine and aspirin patients who did not receive abciximab (median 11 hours, interquartile range 9 to 12, p = 0.57). Thus, in patients who receive coronary stents, stent thrombosis occurs much earlier after the procedure in patients treated with ticlopidine and aspirin than in patients treated with anticoagulation therapy.