Objectives: To cross-validate the existing peak rate of oxygen consumption (VO_2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO_2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO_2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg^–1×min^–1) was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO_2peak with measured VO_2peak using paired t-tests. For individual differences limits of agreement (LoA) were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO_2peak did not exceed ±1 metabolic equivalent (MET) in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs) were large in all predictions. At the individual level, none of the equations were valid predictors of VO_2peak (ml×kg^–1×min^–1). Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO_2peak (ml×kg^–1×min^–1) were found. Most tested equations were invalid predictors of VO_2peak at group level and all were invalid at individual levels.