Background: This study had two aims: to investigate the capacity of individuals with intellectual disabilities (ID) to make decisions about their medications, and to evaluate whether the provision of training (information) sessions on medications would increase their capacity. Method: Twenty-eight adults (18 male and 10 female), with a mild to moderate ID were included in this study and they were taking either Epilim, Metformin or Haloperidol medications. The participants were split into groups that comprised of participants taking the same medications. Each of the groups received three training sessions on their own medications. Capacity to consent was measured by the Adapted-Assessment of Capacity Questionnaire (A-ACQ), which was specially adapted for each medication type from the original measure (ACQ). Receptive language ability was measured by the British Picture Vocabulary Scale-II (BPVS-II). Results: A two-factor mixed anova analysis indicated that the provision of training had improved the capacity of the participants to give informed consent to taking their medications. Analysis using Pearson's correlations indicated that increased levels of receptive language ability correlated with greater ability to give informed consent to taking medication. Conclusions: The provision of information that is formatted in a way that individuals with ID can understand may be a useful way to increase knowledge on medications. Further research that investigates the provision of information with larger samples is warranted.