Aim: Assessing disparities in morbidity between salaried workers and the specific population of self employed workers, covered by a special mandatory statutory sheme: the self employed workers national healthcare insurance fund (RSI). Methods: Incidence rates of affections with exemption of co-payment(reimbursed at a 100% replacement level)are compared between the population covered by the salaried workers national healthcare insurance fund and the population covered by the RSI. The two populations differ strongly regarding important health determinants: age and sex ratio. To control for this confounding factors we perform a direct age and sex standardisation.Results: The age and sex adjusted overall incidence rate of severe chronic illness is significantly higher for the self employed workers than for the salaried workers. By disease subgroup analysis there is no significantly difference for cancers; the severe psychiatric diseases are significantly lower for the self employed workers; diabetes mellitus, severe high blood pressure, cardiovascular disease and dementia are significantly higher for the self employed workers.Conclusion: Some hypotheses are presented to explain these differences. Other work is to be undertaken to explore them. This findings argue for a sanitary prevention policy toward the self employed worker population in the prospect to decrease this morbidity disparities.Prat Organ Soins. 2011;42(1):1-9