Behaviour analysts typically set a criterion for correct responding to determine when a skill is considered mastered. Practitioners often pre-set the criteria arbitrarily as there is little empirical evidence about the effects of differing mastery criteria on the maintenance of skills. The aim of the current study was to evaluate the effects of differing mastery criteria on skill maintenance. The impact of 80%, 90%, and 100% correct responding on the maintenance of sets of skills taught during discrete trial teaching was evaluated. Four children aged between 5- and 9- years-old with a diagnosis of Autism Spectrum Disorder participated in the research. Participants were taught to recognise words. Sets of words were taught until each of the three criteria were met, skill maintenance was probed after one week, and again once per week for another three weeks. Results demonstrated that skills were maintained at a response accuracy similar to the mastery criteria employed; with mastery criteria of 100% reliably producing higher levels of accurate responding during maintenance than a mastery criteria of 80% and 90%.