Fatigue is a disabling symptom in Multiple Sclerosis (MS), but fatigue management strategies have not been systematically evaluated. The objective of this study was to investigate the effects of 'Pacing', on the experience of fatigue measured by self-report ratings and cognitive performance decrement. Using an experimental design, 29 MS participants and 31 matched healthy control participants were separately randomised to one of three conditions: continuous verbal list learning, alternating verbal list and visual memory tasks, or verbal list learning alternating with rest ("pacing"). Participants were assessed on parallel forms of the Brief Repeatable Neuropsychological Battery (BRB-N) before and after the intervention. Baseline depression (CES-D) and fatigue (FSS) questionnaires and 4 Fatigue Visual Analog Scale (FVAS) ratings spaced through the 90- minute schedule were completed. Results revealed the MS group had significantly higher baseline depression and fatigue scores. A mixed ANOV A (group x condition x cognition time I, time 2) for cognitive performance revealed: the MS group's performance was worse than the healthy control group's (p<.OOI); both groups' performance was worse after the mental effort (p<.OOI) required by the intervention, whilst experimental condition had no effect upon cognitive performance. A mixed ANOV A (group x condition x self-reported fatigue at 4 time points) for FVAS ratings revealed both groups reported increased fatigue over time (p<.OOI) yet fatigue did not differ significantly between groups or conditions. The conclusion drawn was effortful mental tasks increased self-reported fatigue and reduced cognitive performance equally in both MS and healthy participants. This supports cognitive fatigue as an inducible and measurable construct. In this study, ' Pacing' had no effect on cognitive performance decrement or self-reported fatigue. With direct clinical implications for MS fatigue management courses that incorporate these strategies further systematic evaluation is warranted.