introduction. According to the Theory of the Duaux States, homozygotes Val on the COMT gene would have better flexibility capacities, while Met/Met individuals would promote stability capacities. These genotyping effects would be amplified in ageing as declining brain resources increase the influence of genetic differences on cognition. Our aim is to investigate the influence of nucleotide polymorphism COMTVal108/158Met on executive functions in normal ageing. Method. Three executive functions were evaluated through different tasks in young (N = 55) and older participants (N = 45) with one of the genotypes of the COMT gene (Val/Val, Val/Met, and Met/Met). We carried out t tests between the two groups and one ANOVA 6 (Group: Jeunes-Met/Met, Jeunes-Val/Met, Jeunes -Val/Val, Avenue Met/Met, Age Val/Met and Age Val/Val) X 3 (Executive operation: Inhibition, Flexibility, and Update) with repeated measurements with executive operation as an intra-subject factor (p <, 05). Results. Young and older people differed significantly among the three executive functions. Within young and older groups, no significant differences between genotyping groups could be identified. Interestingly, the Age Val/Val group had a lower performance than the Jeunes-Val/Val group in inhibition. Discussion. As expected, we found an age effect on all executive functions. The difference between Jeunes-Val/Val and Age Val inhibition supports the idea of a decrease with advanced performance when a stability component is required by task in individuals with a less favourable genotype for this component.