The Bolivian government issued a regulation for rabies control in November 2005, owing to increasing the prevalence of dog and human rabies cases in recent years. An assessment of rabies-vaccination coverage and other factors that might influence the success of the on-going vaccination campaign was needed. The objective of this study was to investigate dog rabies vaccination coverage and risk factors associated with dogs being unvaccinated against rabies, and profiles of the owned-dog population in Santa Cruz de la Sierra, Bolivia, where dog rabies was endemic. Mainly due to logistical reasons, the WHO's expanded programme on immunization cluster-survey method was used. The 390 households were included in the study. Information about dog population and management characteristics was obtained for 542 dogs from 301 households. On average, households had 1.4 dogs and 1.8 dogs per dog-owning household (median = 1). The human-to-dog ratio was 4.6 : 1. During the last 1 year prior to the study, of the 539 dogs aged >or=1 month, 463 (85%; 95% CI 79-91; design effect 3.6) were classified as vaccinated. Amongst the study dogs, dogs aged 1-11 months were the higher risk of dogs not being vaccinated (OR = 8.2; 95% CI 4.3-15.6; P < 0.01). Almost two-thirds of the study dogs were allowed to roam freely throughout the day or in part. Community education efforts should address the importance of dog ownership and movement restriction, and the need to vaccinate young dogs.