Objectives Older people reporting subjective memory complaints (SMCs) may have a greater risk of cognitive decline. Multidomain lifestyle interventions are a promising strategy for the prevention of cognitive decline. The aim of this study was to investigate whether the presence of SMCs affects the efficacy of a 2-year multidomain lifestyle intervention on cognition.Methods This study is part of the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) project. Participants (a subsample of 568 individuals, baseline age 60-77 years) were randomized (1:1) to receive a 2-year multidomain lifestyle intervention group including dietary advice, exercise, cognitive training, and vascular risk management, or regular health advice control group. Cognitive performance was assessed at baseline and at 1- and 2-year visits, using a neuropsychological test battery, including tests assessing memory, executive functions, and processing speed. Participants rated the frequency of SMCs using the Prospective and Retrospective Memory Questionnaire.Results Having more retrospective SMCs was linked to a less favorable cognitive trajectory over 2 years. The difference between the intervention and control groups in annual change in tested memory performance was 0.077 (95% CI, 0.008-0.146) among those reporting more retrospective SMCs and -0.011 (-0.074 to 0.053) among those with less SMCs; interaction effect p = .019. No other interactions between SMCs and intervention allocation were observed.Discussion A lifestyle intervention may be beneficial for older adults with and without SMCs. Persons having more retrospective SMCs may benefit more from the intervention regarding memory functioning. Clinical Trials Registration Number: NCT01041989Discussion A lifestyle intervention may be beneficial for older adults with and without SMCs. Persons having more retrospective SMCs may benefit more from the intervention regarding memory functioning. Clinical Trials Registration Number: NCT01041989