The objective of the study was to explore the barriers and facilitators to using body mass index (BMI) for preschoolers. A survey was administered to a random sample of 600 pediatricians and family physicians in Michigan addressing usual practice for BMI charting, barriers, perceived influence of BMI chart innovations on the likelihood of increasing use of BMI and participating in training regarding obesity management. The response rate was 52%. Few respondents report that they generally use BMI charts for preschoolers (24%). The most frequently endorsed barrier was time and complexity involved in explaining BMI (70%). Respondents endorsed innovations such as color-coded charts (60%), and the inclusion of management recommendations (61%) as strong influences on the likelihood of using BMI more often. Frequently endorsed training modalities were workshops (47%), online (45%), and DVD (43%). Efforts to increase physician use of BMI should address methods to simplify communication of BMI, such as with color-coded charts, and provision of management recommendations based on BMI findings.