The objective was to compare the performance of the International Physical Activity Questionnaire (IPAQ) and Baecke questionnaire to estimate maximal oxygen uptake (VO2max) in healthy older women. One hundred healthy women aged 60 years and older answered the IPAQ and Baecke questionnaires and underwent a cardiopulmonary exercise test. The 6-min walk (6MWT), timed up and go (TUG), and handgrip strength test (HST) were also performed. Mean age and body mass index were 68.5 ± 6.3 years and 27 ± 4.7 kg/m2, respectively. No significant correlation was seen between VO2max, IPAQ and Baecke questionnaires. IPAQ did not correlate with any functional tests while Baecke correlated weakly with the 6MWT and TUG test. VO2max correlated significantly with the 6MWT (r = .38; p = .0001), HST (r = .34; p = .001), and TUG (r = −.41; p = .0001). In a multivariate regression model, TUG was the best estimator for VO2max (R2 = .217; p = .0001). In conclusion, IPAQ and Baecke questionnaires do not associate significantly with VO2max in older women.