Purpose: To examine dietary exposure to 25 pesticide residues in several diet groups including omnivores, pesco-vegetarians, vegetarians and vegans while accounting for the farming system (organic or conventional) of plant-based foods consumed. Methods: Organic and conventional consumption data in combination with data on pesticide residues in plant-based foods were used to derive estimated dietary exposure to pesticide residues. Pesticide residue exposure was estimated based on observed data, and using two scenarios simulated for 100%-conventional and 100%-organic diets in 33,018 omnivores, 555 pesco-vegetarians, 501 vegetarians and 368 vegans from the NutriNet-Santé study. Pesticide residue exposure across groups was compared using Kruskal-Wallis tests. Results: Exposure levels varied across diet groups depending on the pesticide studied. The highest exposure was observed for imazalil in all groups. Vegetarians appeared to be less exposed to the studied pesticides overall. Compared to omnivores – apart from pesticides authorised in organic farming – vegetarians had lowest exposure. The 100%-conventional scenario led to a sharp increase in exposure to pesticide residues, except for pesticides allowed in organic farming and conversely for the 100%-organic scenario. Conclusions: Despite their high plant-based product consumption, vegetarians were less exposed to synthetic pesticides than omnivores, due to their greater propensity to consume organic