The dietary and health traits of organic food (OF) consumers have not been comprehensively described. The aim of this study was to identify factors associated with OF consumption. Data were collected from 54 283 participants from the NutriNet-Santé cohort using self-administered web-based questionnaires. Occasional organic food consumers and regular organic food consumers (ROFC) were compared with non-organic food consumers (NOFC) using logistical regression providing an OR and 95 % CI. Adherence to the French food-based guidelines and interactions between nutritional knowledge and OF consumption in adherence to dietary guidelines were investigated. Medical history was also assessed in relation to OF consumption. Compared with NOFC, ROFC were more likely to be vegetarian (OR 9·93; 95 % CI 7·42, 13·29 in women; OR 13·07; CI 7·00, 24·41 in men) and were less likely to be aware of nutritional guidelines regarding meat consumption (OR 0·37; CI 0·34, 0·40 in women; OR 0·41; CI 0·36, 0·47 in men). Compared with NOFC, ROFC had a lower risk of type II diabetes, hypertension and CVD; however, this effect was only significant for men. In contrast, organic consumers were more likely to report food allergies. Consuming OF appeared to affect the relationship between nutritional knowledge and adequate intake of meat/poultry/seafood/eggs and starchy food among both sexes. Our study provides new insights into the diet- and health-related behaviours of OF consumers in a large sample of participants residing in France. This should be taken into account in future studies investigating relationships between health and OF consumption.