Active commuting (walking or biking) to school has grown in popularity as a method of promoting a healthy and physically active lifestyle for youth. Before implementing full-scale active commuting campaigns, however, potential environmental factors (also known as the built environment: accessible sidewalks, safe places, pedestrian walkways) and current commuting patterns of youth must be assessed. Active commuting by walking is the main focus of the current study; therefore, the main purpose of this investigation was to determine if a relationship exists between the walking suitability (assessment of the built environment) of 14 elementary schools and the actual commuting patterns (i.e., walking) of 5th-6th grade students in Mesa, Arizona. The walking suitability assessment (focused on sidewalks, curb ramps, buffers, traffic patterns) was used to determine overall suitability scores for each school. To measure the commuting patterns and demographic characteristics of students, a participant questionnaire (included a 5 day recall of commuting patterns, demographic questions, and distance to school) was administered to 393 students. The average walking suitability score of all schools was 14.3±23.9, translating to an overall poor rating. Possible scores ranged from –1 to 99+. Based upon the Mann Whitney U test, the median walking suitability score was 3.7 (a “good” rating); the 25th percentile score was 2.9 and the 75th was 22.3. Scores were not statistically different between the busing strata, U(12) = 11.0; exact alpha was p = .09. A moderate inverse association was revealed (r = -0.3, p = .01) between the walking suitability of all 14 schools and the reported number of days spent walking to school by all students (n = 393). A moderate inverse association was also seen between the walking suitability score and the reported number of days spent walking home from school (r = -0.3, p = .01). Additionally, total walking trips during a typical week was related to the distance to school in an inverse direction (r = -0.55, p = .01). These findings have implications for practitioners and school personnel who are considering implementing active commuting programs. For example, a school with poor walking suitability may be characterized by high-speed traffic patterns that impede the safety of walking to school. Examining such a measure of the built environment should be considered when examining physical activity patterns, such as active commuting.