OBJECTIVES: Multiple chronic conditions (MCCs) are related to increased health care services and cost and decreased quality of life. Due to the broad implications of MCCs and Body Mass Index (BMI) for Health Policy, this study evaluated the relation between MCCs and BMI through population estimates, accounting for demographic characteristics and risk factors. METHODS: Data from the cross-sectional telephone survey Behavioral Risk Factor Surveillance System, for years 2011 and 2013 (N=12,624), was used to obtain the self-reported count of chronic conditions (CCs) and BMI. This study included adults 18 years or older living in Puerto Rico with 1 to 6 diagnoses of CCs, and with BMI (kg/m^2) between 20.0 and 45.99. Females that reported pregnancy at time of survey were excluded from analysis. Survey-weighted summary statistics were estimated and Poisson regression coefficients and standard errors (S.E.) calculated using generalized linear models in R. RESULTS: The study population (n=7,830) represented approximately 1,462,598 adults (55.9%, 95% confidence interval [C.I].: 54.7-57.0). The estimated MCCs prevalence was 56.1% (95% C.I.: 54.7-57.0), whereas the BMI mean was 28.7 kg/m^2 (S.E=0.08). After adjusting by age, gender, income, smoking status, binge drinking, and high cholesterol the regression model showed that the possibility of reporting more than one chronic condition increases 2.0% (S.E. = 0.16%) with an increment in a BMI unit. The most prevalent combinations of two and three chronic conditions were arthritis-hypertension (10.7%, 95% C.I.: 9.7-11.7), and diabetes-arthritis-hypertension (5.4%, 95% C.I.: 4.7-6.1). CONCLUSIONS: Study results suggested that in adults living in Puerto Rico with a chronic condition, the possibility of reporting an additional chronic condition increases as BMI increases. Decision makers should use these findings to support population interventions for weight reduction, policy evaluation, and development of MCC guidelines in an effort to improve quality of life and decrease health care spending.