Objectives: The purpose of this study is to evaluate the readability and quality of Internet information related to vocal health, voice disorders and voice therapy. Study design: This is a cross-sectional study. Methods: Eighty-two websites were included. Websites were then analyzed; their origin (clinic/hospital, non-profit, government), quality (Health On the Net [HON] certification and DISCERN scores) and readability (Ateşman readability formula and Bezirci-Yılmaz new readability formula) were assessed. Statistical analysis was used to examine differences between website origin and quality and readability scores and correlations between readability instruments. Results: Of the 82 websites, 93% were of private clinic/hospital, 6% were of non-profit organisation and 1% were of government. None of the 82 websites were HON certification, and the mean score of the item determining the general quality measure in DISCERN was 1.83 in a five-point scale. The mean of Ateşman readability formula value was calculated as 50.46 (±8.16). This value is defined as ‘moderately hard’ according to the readability scale. The average of Bezirci-Yılmaz new readability formula value is 13.85 (±3.48). This value is defined as 13th and 14th grade. Conclusions: The quality of Internet-based health information about the voice is generally inadequate, and the sites examined in this study may be limited due to high readability levels. This may be a problem in people with poor literacy skills. For this reason, it is very important for speech and language therapists and other health professionals to evaluate and monitor the quality and readability of Internet-based information.