Obesity is becoming an epidemic in Latin American countries. Genetic analyses of endophenotypes for obesity, such as body mass index (BMI), are quite useful for research. In this study, we analysed two functional polymorphisms in the dopamine receptor 4 (DRD4) and dopamine transporter (SLC6A3) genes. A sample of 232 Colombian young subjects were recruited and evaluated for BMI. Two functional polymorphisms in the DRD4 and SLC6A3 and genes were genotyped by PCR and electrophoresis. A significant association was found between BMI and the polymorphisms in DRD4 and SLC6A3 genes. DRD4 4/4 genotype was associated with a lower mean BMI and SLC6A3 10/10 genotype was associated with a higher mean BMI. Our work provides additional novel findings about the association of dopaminergic genes with BMI in healthy young adults. In addition, our study is one the first analyses of candidate genes for BMI in Latin American samples.