The Audit Commission in the UK recommends that patient information leaflets (PILs) should be audited by health professionals using a formal readability test. However, no such study on antiepileptic drugs (AEDs) has been identified in a Medline search. The aim of this study was to audit the readability of PILs prepared for marketed proprietary AEDs in the UK. Twelve PILs were compared with six antiepileptic drug articles from medical journals and six headline articles from UK newspapers. The Gunning Fog index and the Flesch Reading Ease index were calculated for each PIL and article. The results of the Gunning Fog index and the Flesch Reading Ease score were compared using the Kruskal-Wallis non-parametric test. PILs were shown to have a statistically significant lower mean reading age than the medical articles and newspapers (P < 0.001). The Gunning Fog index and Flesch Reading Ease score showed that PILs had a mean reading age of 8.8 and mean readability score of 69, respectively. In conclusion, the PILs prepared for proprietary antiepileptic drugs in the UK are suitable for the reading age of the general adult population.