Although anthropometric parameters have been extensively studied regarding their relationship to physical function status, the association between these parameters and the activity of daily living (ADL) function remains controversial. We investigated whether BMI or mid-upper arm circumference (AC) is an indication of variation in the physical functioning of the frail elderly. The present study was a prospective cohort analysis of 543 community-dwelling frail elderly. Data included the participants' demographic characteristics, basic ADL, comorbidity and anthropometric measurements at baseline and at 2-year follow-up. Logistic regression models were used to investigate the association between ADL status and anthropometric measurements during the study period. Among the 543 participants, 418 maintained or improved their ADL status, while 125 showed an ADL decline during the study period. Multivariate logistic regression analysis showed that BMI and AC levels or ADL status at baseline were not independent predictors of the loss of ADL function or the decline in these anthropometric measurements during the study period, respectively. However, the decline in BMI and AC levels and the loss of ADL function were associated with each other during the study period. There is an association between the negative changes in anthropometric measurements during the follow-up period and the decline in ADL function during a 2-year follow-up in community-dwelling frail elderly.