Anxiety disorders are a group of psychological and neurological problems that represent various forms of abnormal or pathological fear and anxiety (Orozco & Baldares, 2012). Even though around 14% of the world population has suffered from an anxiety disorder, their causes are not entirely clear (Bandelow & Michaelis, 2015). The bio-psychological theory of Gray (1987) suggests that there are two systems that govern our personality, the BIS/BAS systems. The behavioral inhibition system (BIS) describes a fearful reacting-style to novelty, and is related to a greater social reticence. Both the COMT and BDNF have been postulated as candidate genes for anxiety disorders. The polymorphisms of greatest interest are the rs4680 of the COMT gene that plays an essential role in the degradation of extracellular dopamine in the prefrontal cortex, and the rs6265 of the BDNF gene that has been related to the activation of the amygdala as well as behaviors associated with anxiety (Johnson, Carver, Joormann & Cuccaro, 2016). The aim of this study was to evaluate the possible relationship between the rs4680 polymorphism of the COMT gene and the rs6265 polymorphism of the BDNF gene with the BIS/BAS system in a sample of the population of the city of Bogotá. According to the results obtained, it is evident that the frequency of the risk allele A of the rs6265 polymorphism of the BDNF gene is greater in the group with BIS sensitivity than in the group with BAS sensitivity, which allows to identify the risk allele A of as a possible predisposition factor for a BIS sensitivity.