Summary Purpose To assess the reporting of adverse events (AEs) in randomised controlled trials (RCTs) of antiepileptic drugs (AEDs) using the CONSORT statement for harms 2004, and to determine if reporting has changed since introduction of this standard. Principal results One hundred and fifty two RCTs were included from a search of papers published between 1999 and 2008 inclusive. We identified 23 criteria in the CONSORT statements. The mean number of criteria met per trial was 11.3 (95%CI 10.6–12.0). Commercially funded studies met 12.6 and non-commercially funded met 9.4 ( p < 0.001). Trials recruiting adults met 12.5 and trials recruiting children met 9.3 ( p < 0.001). Trials published before 2004 met 11.6 and trials published after 2004 met 11.1 ( p = 0.53). Commercially funded trials met the majority of criteria more than non-commercially sponsored trials, particularly for definition of AEs (RR 3.15, CI 1.67–5.95) and the use of a validated dictionary of terms (RR 3.46, CI 1.41–8.44). Definitions for AEs (RR 2.32, CI 1.07–5.02) and details of analyses (RR 2.05, CI 1.01–4.15) were reported in adult trials more often than trials in children. Major conclusions Reporting of AEs in RCTs of AEDs is poor and has not improved since the publication of the CONSORT guidelines on the reporting of harms. Commercially funded trials were better reported than non-commercially funded trials and trials recruiting adults were better reported than trials recruiting children. These findings have serious implications as poor reporting precludes bias being detected and hinders adequate risk benefit analyses. Journal editors, authors and reviewers should be encouraged to follow current guidance.