One of the defining differences between mild cognitive impairment (MCI) and dementia is the degree of independence in everyday activities. Effecting memory-related behavioural change in MCI could help maintain daily function and prolong the time before onset of dependency. However, it is well known that changing previously well-established behaviours is difficult to achieve. We conducted a randomised controlled trial to evaluate the effectiveness of a multidisciplinary group-based intervention programme in changing everyday memory behaviour in individuals with amnestic MCI. The intervention provided evidenced-based memory training and lifestyle education to optimise memory behaviour. Fifty-four participants were randomly assigned to treatment or waitlist-control conditions. Consistent with our primary goal, treatment participants showed an increase in memory-strategy knowledge and use from pre-test to immediate post-test, and these gains were maintained at three-month post-test relative to waitlist controls. There were no group differences in memory beliefs or on laboratory tests of objective memory performance. The increase in memory-strategy knowledge and use was associated with the degree of participation in the programme. Individuals with MCI, therefore, can acquire and maintain knowledge about memory strategies and, importantly, can change their everyday memory behaviour by putting this knowledge into practice. This incorporation of practical memory strategies into daily routines could potentially provide the means for maintaining functional independence by individuals with MCI, an issue to be addressed in future research.