This study aims to evaluate cardiovascular drug labels from the perspective of how readable the text materials are.Comparison of drug labels written in accordance with the 1997 Brazilian legislation with those written in accordance with the 2003 Brazilian legislation, with journalistic text and scientific essays using as tool the Flesch Index.The journalistic text had an average Flesch Index of 62.6%; the scientific essays, 23.5%; the drug labels written in accordance with the old legislation, 43.8%; and those written in accordance with the most recent legislation, 47.2%.Drug labels are more readable than scientific essays and less readable than journalistic texts; they were classified as difficult to read.Text readability formulas are an objective measure that may improve the search for better-written communication materials and thereby a greater understanding of drug labels by patients. However, a more detailed validation of an objective measure of text evaluation should be considered by the health authorities of each country, with their own language as basis.