The aims of the study were to evaluate the relationship between Modified Shuttle Walk Test (MSWT) with peak oxygen uptake ( V ˙ O 2peak ) in overweight/obese people with primary hypertension (HTN) and to develop an equation for the MSWT to predict V ˙ O 2peak . Participants (N = 256, 53.9 ± 8.1 years old) with HTN and overweight/obesity performed a cardiorespiratory exercise test to peak exertion on an upright bicycle ergometer using an incremental ramp protocol and the 15-level MSWT. The formula of Singh et al was used as a template to predict V ˙ O 2peak , and a new equation was generated from the measured V ˙ O 2peak -MSWT relationship in this investigation. The correlation between measured and predicted V ˙ O 2peak for Singh et al equation was moderate ( r = 0.60, P −1 minute −1 , SEE% = 21%. The correlation between MSWT and measured V ˙ O 2peak as well as for the new equation was strong ( r = 0.72, P −1 minute −1 , SEE% = 19%. These results indicate that MSWT does not accurately predict functional capacity in overweight/obese people with HTN and questions the validity of using this test to evaluate exercise intolerance. A more accurate determination from a new equation in the current study incorporating more variables from MSWT to estimate V ˙ O 2peak has been performed but still results in substantial error.