We looked for an association between the DRD4 exon III and 3′UTR DAT1 polymorphisms and the personality traits of 200 unrelated young women of Polish descent. Personality traits were measured using the NEO-FFI questionnaire. The 7-repeat variant of the DRD4 gene was associated with a lower level of conscientiousness (F=4.69, df=1, p=0.032, Cohen’s f=0.16). In addition, a statistically significant interaction was observed between the DRD4 and DAT1 polymorphisms with respect to neuroticism (F=3.92, df=1, p=0.049, Cohen’s f=0.14). Further research is required to explain the role of variability in the dopaminergic system genes and how this affects the development of personality traits.