Abstract Background Work is vital to people’s health and quality of life. The Convention on the Rights of Persons with Disabilities affirms the right to work on an equal basis with others including an opportunity to earn a living by work, but evidence shows that people with intellectual disability (ID) are at greater risk of unemployment and social exclusion. Due to the lack of comprehensive data for longitudinal follow-ups, information on long-term labor market participation (LLMP) in people with ID is scarce. This study aimed to investigate factors of importance for LLMP in individuals with ID in Sweden. Methods The study was based on data from the upper secondary school for pupils with ID between 2001 and 2020 (N = 26,905) and from the longitudinal integrated database for health insurance and labor market studies. A sample of gainfully employed in 2011 (n = 2,719), was followed with respect to LLMP until 2020. Odds ratios (ORs) with 95% confidence intervals (CI) for associations between educational, sociodemographic, and work factors and LLMP (i.e. gainful employment throughout the follow-up), were estimated stratified on sex. Results LLMP was twice as likely in men compared with women, OR 2.06 (1.78-2.58) as was work in the private sector. Factors of significance for LLMP in men and women alike were: completed national education program, OR 3.40 (3.06-3.86) and OR 2.91 (2.40-3.54), parents’ education; compulsory school in mothers’, OR 1.22 (1.06-1.41) and 1.24 (1.00-1.55) and in fathers’ OR 1.35 (1.17-1.56) and 1.49 (1.20-1.85), while municipality of residence was significant only in men, OR 1.30 (1.10-1.56). Conclusions Public health prevention for disadvantaged groups requires accurate and up-to-date knowledge. Using unique register-based data, this is the first study on LLMP in people with ID in Sweden. Knowledge on what social determinants may strengthen LLMP is important since limited LLMP increases the risk of missing out on health benefits that employment may offer. Key messages • There was a significant gender difference in long-term labor market participation in people with intellectual disability in Sweden. • There is a need for increased knowledge on what social determinants may strengthen long-term labor market participation in people with intellectual disability.