Health information posted on the Internet has become a popular mode of communication with the population at large because millions of people now use the Internet to gather health information. Many studies on readability have shown that patient education information is frequently written at the reading level too high for the average population to understand, and the same holds true for health information on the Internet. The aim of this study was to determine the readability levels of health information found on diabetesrelated websites displaying HONcode logo, which indicates to high quality of the information provided. The 99 websites tested for readability using the Flesch Reading Ease formula and Flesch-Kincaid level showed FRE score 2.1 to 79.6, with the mean 41.7 (10^th grade, 8^th month Flesch-Kincaid level), which indicates that 86.9% of these materials would be too difficult to read for the average adult population. It is suggested that the readability level, and the name of the formula used, be used on the websites themselves to help the Internet users decide which sites could be of the greatest benefit to them.