Objectives - To understand how individuals with a long-term health condition adjust their behavior in the labor market by working part-time. Methods - The study is based on data from the 2003 Ten-Year Health Survey, conducted by INSEE, in which 35,073 people, representative of the entire French population, were interviewed. The scope of the study was limited to employed individuals aged 20 to 65. Health status is assessed using the "Long-Term Illness" (ALD) indicator. The approach is econometric: a systematic analysis of the significance of this indicator is conducted in multiple regression models where the dependent variables represent part-time employment, whether chosen or imposed. Results - Poor health is associated with a higher probability of working part-time; however, according to the survey, the number of cases where part-time work is sought for health reasons is three times higher than the number of official claims for therapeutic part-time work; finally, in some cases, part-time employment is “imposed.” Discussion-Conclusion - People with chronic illnesses are withdrawing significantly from the labor market, and these withdrawals are only partially offset by the social protection system. (R.A.)