The purpose of this study was to investigate the relationship between cognitive functions, assessed by neuropsychological tests, and instrumental activities of daily living (IADL) ability, assessed by the Assessment of Motor and Process Skills (AMPS) in persons with mild Alzheimer's disease. Fifty-two participants were included in the study. We found significant relationships between the AMPS IADL process ability and Factors 1 (perceptual speed, visuoconstructive ability) and 4 (secondary memory). The AMPS IADL motor ability showed a significant relationship to Factors 1 and 3 (logical memory). The cognitive factors explained 24 26% of the variability in AMPS IADL ability. The results indicate that cognitive functions had a significant impact on IADL ability in this population. However, as 74-76% of the variability in the IADL ability was left unaccounted for by the cognitive functions, it is important to assess both cognitive functions and IADL ability when investigating persons with mild dementia. Further study of the complex interaction between a variety of influencing factors is needed to better understand the consequences of dementia on everyday life functioning.