The distribution of 5-HTTLPR genotype of the serotonin transporter is variable and diverse by region and ethnicity. The main feature of the Moroccan population is its ethnic diversity. However, genetic studies on this population are very limited. Our objective was to determine the frequency of the 5-HTTLPR polymorphism in the Moroccan population. The study involved 100 healthy Moroccan subjects. Our results showed that the distribution of genotypes of polymorphism 5- HTTLPR was in equilibrium with the Hardy-Weinberg with a frequency of homozygosity II estimated at 52% and 20% DD. This frequency is intermediate between the western population and population sub-Saharan Africa.