Participants were asked to carry out a series of simple tasks while following mental control instructions. In advance of each task, they either suppressed thoughts of their intention to perform the task, concentrated on such thoughts, or monitored their thoughts without trying to change them. Suppression resulted in reduced reports of intentionality as compared to monitoring, and as compared to concentration. There was a weak trend for suppression to enhance reported intentionality for a repetition of the action carried out after suppression instructions had been discontinued.