Background and Objectives: The Ventilatory Workload Kinetic Index (VWKI) has been proposed as a clinical instrument to evaluate ventilatory balance-imbalance. On the other hand, the regulated application of scales that allow an integral evaluation of the object of study and their subsequent reliability evaluation should be a continuous. The objective was determined the reliability of the VWKI between two evaluators and its applicability in the clinical field of physiotherapy. Materials and Methods: Methodology was divided into three stages: i) induction period, ii) application of the VWKI, and iii) reliability process. Results: The VWKI total score obtained excellent inter-rater reliability (ICC=0.913, p<0.05). The airway resistance (AR) showed moderate inter-rater reliability (ICC=0.528, p<0.05), while the use of accessory musculature (UAM) showed poor inter-rater reliability (ICC=0.483, p<0.05). The physiotherapy care prioritization system, for both evaluator A (EA) and evaluator B (EB), the total VWKI score was significantly higher in priority 1 (p=0.001; p<0.05, respectively). The Total VWKI score by services, it was observed that both EA and EB rated the VWKI significantly higher in the intensive care unit (ICU) than in Medicine and the other services (p=0.001, p=0.0001 and p<0.05, p<0.05, respectively). Conclusions: VWKI have of excellent reliability your the total score. Also, have consistency with the system of prioritization of physiotherapy care, and the ability to determine the severity of respiratory clinical pictures.