The systematic differences of gender representation across occupations, gender-based occupational segregation, has been suggested as one of the most important determinants of the still existing gender wage gap. Despite some signs of a decreasing trend, there is evidence that occupational gendered segregation is persistent even though gender differences in human capital variables have been disappearing. Using an agent-based model we provide a framework that introduces discriminatory behavior based on labour market theories of discrimination where workers and firms can exhibit gendered preferences. The introduction of discriminatory behavior transforms the otherwise random dynamics of occupational choice into a persistent gender-based occupational segregation consistent with empirical evidence.