Background & Aims : The aim of this study was to investigate dual-task interference on maximum grip force while performing a grip and lift task. Moreover, the influence of handedness on maximum grip force, and the relationship between maximum grip force and subjective difficulty were also investigated. Methods : Eleven subjects took part in the study. The study experiment was comprised of one single task and three dual tasks : 1) grip and lift task, 2) grip and lift task with single-leg stance, 3) grip and lift task with eyes closed, and 4) grip and lift task with calculation. The experiment was conducted in both hands separately. Maximum grip force of four fingers (dominant/non-dominant×thumb/index finger) was compared among tasks and between hands. Results : We found that maximum grip force was increased mainly by the cognitive dual task in both hands, and that there was no difference between hands in the same task. There was a positive correlation between the perceived difficulty and maximum grip force in the dominant hand. Conclusion : Our results suggest that maximum grip force could serve as an objective index for