Road traffic injuries in general and pedestrian injuries in particular are a major public health problem in Mexico, especially in large urban areas. Analysis of mortality and road crashes at the national level was done using routine data recorded on death certificates. Fatality rates for different age groups were estimated by region for the year 2000. These data were supplemented by a cross-sectional study of pedestrian injuries in Mexico City based on death certificates information for pedestrians who lived and died in Mexico City between 1994 and 1997. Participant observation of physical spaces where crashes occurred was carried out. The spaces were filmed and in-depth interviews of survivors conducted. Road traffic crashes were responsible for approximately 17,500 deaths in Mexico during 2000. The mean age of the victims was 37 years. Mexico lost an average of 30 years of productive life for each individual who died in a traffic crash--525,000 years in 2000. An estimated 9500 (54.3%) of all fatalities were pedestrians, and for every pedestrian death there were 13 others who sustained nonfatal injuries requiring medical care. The overall crude mortality rate for pedestrian injuries in Mexico City was 7.14 per 100,000 (CI 6.85-7.42). A concentration of deaths was observed in 10 neighborhoods at specific types of street environments. The underlying factors included dangerous crossings and the absence or inadequacy of pedestrian bridges, as well as negative perceptions of road safety by pedestrians. In conclusion, this study demonstrates the importance of elucidating the underlying contextual determinants of pedestrian injuries.