Prospective memory (PM) is the ability to perform a planned action at a future time, while engaging in unrelated tasks. PM is highly relevant to independent functioning and quality of life. Moreover, PM impairment independently predicts problems in activities of daily living among older adults after accounting for the effects of psychosocial factors and other neurocognitive functions such as retrospective memory (RM) and executive functions. Research has also shown that older adults have moderate declines in PM, assumed to be associated with age-related changes in the prefrontal cortex. Functional near-infrared spectroscopy (fNIRS) is a relatively new neuroimaging method in the study of cognition. It is a feasible alternative to other imaging techniques due to its suitability for measuring activities in the prefrontal cortex, which has been previously associated with PM processes. Despite the extensive body of research on age-related PM decline, there are several gaps in the current literature. Research revealed a phenomenon, named the age-PM paradox whereby PM deficits for older adults are more commonly observed in laboratory-based PM tasks than naturalistic (everyday) tasks. Implementation intentions is a metacognitive strategy typically used to facilitate goal attainment and has also been applied as a brief intervention to improve PM. This strategy requires individuals to specify exactly where and when an action is will be completed in the format “If I see X, then I will do Y”. However, the benefits this brief strategy in improving PM have also yielded mixed results. Lastly, understanding the neural basis of PM using fNIRS and a laboratory-based PM tasks have largely been unexplored. Thus, the present thesis aimed to investigate PM in older adults across both laboratory and ecological tasks, the effects of implementation intentions on PM in older adults, and the neural correlates of PM using fNIRS.