This study assesses differential labour performance by body mass index (BMI), focusing on heterogeneity across three distinct employment statuses: unemployed, self-employed and salaried. Data were drawn from the Korean Labor and Income Panel Study. The final sample included 15,180 person-year observations (9645 men and 5535 women) between 20 and 65 years of age. The findings show that (i) overweight/obese women are less likely to have salaried jobs than underweight/normal weight women, whereas overweight/obese men are more likely to be employed in both the salaried and self-employed sectors than underweight/normal men, (ii) overweight/obese women have lower wages only in permanent salaried jobs than underweight/normal weight women, whereas overweight/obese men earn higher wages only in salaried temporary jobs than underweight/normal weight women, (iii) overweight/obese women earn lower wages only in service, sales, semi-professional and blue-collar jobs in the salaried sector than underweight/normal weight women, whereas overweight/obese men have lower wages only in sales jobs in the self-employed sector than underweight/normal weight women. The statistically significant BMI penalty in labour market outcomes, which occurs only in the salaried sector for women, implies that there is an employers’ distaste for workers with a high BMI status and that it is a plausible mechanism for job market penalty related to BMI status. Thus, heterogeneous job characteristics across and within salaried versus self-employed sectors need to be accounted for when assessing the impact of BMI status on labour market outcomes.