Twenty-four elderly cardiac patients were asked about their weekly vigorous exercise to predict maximal oxygen uptake (VO2max) using an equation from Ainsworth et al. This predicted VO2max was compared to values from three other equations from Milani et al. No differences in males and females were found. The predicted VO2max and values from two equations overestimated VO2max compared to the most accurate equation for cardiac patients from Milani et al. This suggests the validity of using the Ainsworth equation to predict VO2max in elderly cardiac patients requires further study due to potential overestimation compared to measured values.