Despite the evidence of female progress with regard to women’s role in the labor market, gender inequality remains. Women are still less likely to be employed than men, occupational gender segregation continues, and females continue to earn less than males. The gender wage gap remains wide in several occupational sectors, among which is the information technology (IT) sector. This paper focuses the determinants of gender wage inequality. More precisely, it investigates for statistical evidence of a glass ceiling effect on women’s wages. Based on the quantile regression framework, the empirical analysis extends the decomposition of the average gender wage gap to other parts of the earnings distribution. The main objective is to empirically test whether gender-based wage discrimination is greater among high paid employees, in line with glass ceiling hypothesis. Larger unexplained gaps at the top of the wage distribution indicate the existence of a glass ceiling effect in Portugal.