In the article on Secondary Prevention of Stroke in the December 8, 2014 issue of The Medical Letter (volume 56, page 125), the duration of treatment with clopidogrel plus aspirin in patients who have had a stroke or TIA should be limited to 21 days, not 90 days. This error, which appears twice, in the paragraphs titled "Clopidogrel Plus Aspirin" and "Conclusion", has been corrected in the article as it appears online.