This study investigated the structure and environment of 31 street food vendors in an urban park in the downtown area of Guatemala City. Vendors were interviewed and observed in order to assess the quality, safety, and accessibility of street food. The street food vending in the park consisted of five types: whole meal, snack, beverage, fruits, and carts. A great variety of typical Guatemalan meals, as well as ready-to-eat fruits and hot dog chapin (hot dog with cabbage and avocado cream), were found in the park. The food preparation and handling revealed inadequacies concerning the hygiene. Circumstances, such as the lack of portable water near the vending site and unhygienic sanitary facilities, supported the transmission of pathogens. The clientele was of all ages, and included female as well as the male purchasers. Typical clients came from the surrounding area, i.e. the employees of civil and private offices, commercial businesses, and the non-food vendors of the park. Comparing the economy of street food with the definition of very poor in Guatemala, the prices on the street were often above the daily money needed for a basic food basket. However, a special clientele were the very poor, such as the street children and handicapped people, who earned their meals by helping out at the vending sites. Mainly female street food vendors were found at the whole meal, snack, and refreshment sites whereas men sold predominantly at the carts. For all of the vendors, it was the main source of income and for many families the only one.