The role of employer discrimination in widening labor market differences between men and women has been hypothesized and investigated in different settings. Using a field experiment, this paper examines the presence and magnitude of gender-based discrimination by employers at the point of screening in Tunisia. The study sent out 1,571 fictitious and substantially identical pairs of male and female resumes in response to online job advertisements. On average, women were 2.4 percentage points more likely than men to receive a callback from an employer. However, this average effect hides substantial heterogeneity across economic sectors. In the information technology sector, women were 15 percentage points less likely to receive a callback than men. No discrimination against or in favor of women is found in engineering, whereas in marketing and finance, women were 19 and 4 percentage points more likely to receive a callback, respectively. The paper also finds that, unlike men, women may suffer from discrimination based on their physical appearance. Veiled women were 8.5 percentage points less likely to receive a callback than non-veiled women. Overall, the findings suggest that, at the point of screening, employer discrimination against women in Tunisia is sector specific, and, on its own, it cannot fully explain the complex challenge of female unemployment in the country.