FINGER-NL is a multi-center, randomized, controlled, multidomain lifestyle intervention trial among 1,210 older adults at risk for cognitive decline, with a duration of 24 months. Block-randomization stratified by study site (block sizes of preferably 20–24 participants) was used to centrally allocate eligible participants in a 1:1 ratio to a personalized multidomain lifestyle intervention (HI-group) versus online access to general lifestyle-related health information (LI-group).