In a previous risk factor study in Jakarta we identified purchasing street food as an independent risk factor for paratyphoid. Eating from restaurants, however, was not associated with disease. To explain these findings we compared 128 street food-vendors with 74 food handlers from restaurants in a cross-sectional study in the same study area. Poor hand-washing hygiene and direct hand contact with foods, male sex and low educational level were independent characteristics of street vendors in a logistic regression analysis. Faecal contamination of drinking water (in 65 % of samples), dishwater (in 91 %) and ice cubes (in 100 %) was frequent. Directly transmittable pathogens including S. typhi (n = 1) and non-typhoidal Salmonella spp. (n = 6) were isolated in faecal samples in 13 (7 %) vendors; the groups did not differ, however, in contamination rates of drinking water and Salmonella isolation rates in stools. Poor hygiene of street vendors compared to restaurant vendors, in combination with faecal carriage of enteric pathogens including S. typhi, may help explain the association found between purchasing street food and foodborne illness, in particular Salmonella infections. Public health interventions to reduce transmission of foodborne illness should focus on general hygienic measures in street food trade, i.e. hand washing with soap, adequate food-handling hygiene, and frequent renewal of dishwater.