The high prevalence of cardiovascular risk factors in firefighters is of great concern, since cardiovascular diseases are the main cause of illness and death in this population. The aim of this study was to describe and analyze cardiorespiratory capacity, dietary habits, and body fat percentage in Chilean firefighters. Sixty-five firefighters were recruited and a non-experimental approach of observational and analytical design was used. A cycloergometer exercise test and indirect calorimetry were used to measure maximum oxygen consumption [VO2max] as an indicator of cardiorespiratory capacity, a survey of dietary habits, and bioimpedance to determine the percentage of body fat mass. The mean VO2max was 26,60 ml kg(-1)min(-1) [SD: 6,51]. 83,1% of the participants had excess malnutrition, and 78,5% had excess fat mass. A significant negative relationship was found between VO2max and BMI [rs =-0,468, p<0,001] and body fat percentage [rs =-0,640, p<0,001]. The cardiorespiratory capacity of 89,2% of the subjects was classified as "poor" or "very poor". According to the results obtained and the available evidence, the projection of this study would be the search for protocols that protect aspects of preventive health and maintenance in Chilean firefighters.