Objective To evaluate the effects of whole‐body vibration (WBV) added to a routine activity program on lower limb strength, balance, and mobility among community‐dwelling individuals with mild or moderate dementia, compared with the routine program alone. Methods Fifty‐four older adults (40 women; mean (SD) age: 79.8 (6.1) years) with mild or moderate dementia were recruited from two daycare centers. The participants were randomly allocated to undergo a routine day activity program combined with WBV training (WBV at 30 Hz, 2‐mm peak‐to‐peak amplitude) or the routine program only without WBV for 9 weeks (18 sessions). The primary outcome was functional mobility, measured using the timed up‐and‐go test. The following secondary outcomes were evaluated: Berg Balance Scale, Tinetti balance assessment, time to complete 5 repetitions of sit‐to‐stand, Quality of Life in Alzheimer's disease questionnaire, and Activities‐specific Balance Confidence scale. The attendance rate and incidence of adverse events were also recorded. Results The attendance rate for the training was high (86.0%). The incidence of adverse events was low, with only two of the 27 participants in the WBV group reporting mild knee pain. While significant improvement in timed up‐and‐go, Berg Balance Scale, and Tinetti balance score was found in both groups, none of the outcomes demonstrated a significant group by time interaction. Conclusions WBV training is feasible and safe to use with people with mild or moderate dementia. However, it did not lead to further improvement in physical function and quality of life than the usual activity program provided at the daycare centers. Copyright © 2017 John Wiley & Sons, Ltd.