OBJECTIVES: This study aimed to clarify the impact of the coronavirus disease 2019 outbreak on the levels of activity among older patients with frailty or underlying diseases. A total of 175 patients (79.0±7.0 years) undergoing outpatient or home-based rehabilitation, stratified into groups, based on frailty status. The percentage of patients who went out at least once a week decreased after the outbreak from 91% to 87%, from 65% to 46%, and from 47% to 36% in the non-frail, frail, and nursing care requirement groups, respectively. The proportion of older patients participating in exercise during the outbreak was 75%, 51%, and 41% in the non-frail, frail, and nursing care requirement groups, respectively. The proportion of older patients participating in voluntary exercise after instruction was lowest in the frail group (35%). Older patients with frailty are susceptible to the negative effects of refraining from physical activity and require careful management.