This study evaluates the usefulness of body mass index (BMI) as a preventive screening tool for general health and duty fitness status among firefighters. Two major BMI categorization methods were used: (1) "standard" [low (< 27), medium (> or = 27 < 30), high (> 30)]; and (2) WHO [(normal (< 25), overweight (> or = 25 < 30), obese (> or = 30 < 39), morbidly obese (> or = 39)]. Using the "standard" categorization, nearly 60% of individuals had medium or high BMI's; using the World Health Organization categorization, 80.7% of individuals were found to be overweight, obese, or morbidly obese. Statistically significant, inverse correlation between BMI and each of the following parameters was noted: systolic and diastolic blood pressure, VO2max, METS, and total cholesterol. Inconsistent or statistically insignificant correlation was found between BMI and HDL, Chol/HDL ratio, triglycerides, FVC% predicted, and FEV1 second% predicted. Findings were similar to previous studies of such correlates. BMI continues to prove useful as a screening tool and may be useful in identifying individual firefighters for health and fitness intervention measures.