The purposes of this study were to investigate the rate of change with age of simple lower-limb reaction time (RT) in women and determine the relationship among RT. strength, and physical activity. Independent, community-dwelling women aged 20–89 years (N = 217) were assessed for knee-extension RT, maximal voluntary isometric contractions of the knee extensors (KE), and physical activity level. Trend analysis by ANOVA and regression analysis on RT were performed. Lower-limb RT increased and KE strength and physical activity level decreased linearly across age groups (p < .001). Active women had faster RTs than those of inactive women of the same age (p < .01). From multiple-regression analysis on RT, only 1 predictor variable. KE strength, emerged. Stronger women had faster RTs than those of weaker women (p < .0001), regardless of age and physical activity. Although RT was slower in older women, higher levels of strength and physical activity were associated with faster RTs in this group.