[Health financing conditions in large cities in Brazil].

We evaluated the funding of the Brazilian Unified National Health System (SUS) in municipalities with more than 100,000 inhabitants. The main goal was to evaluate the impact of policies for health resource allocation within the municipal budget. A database was organized with information from revenues reported by municipalities in the Information System on Government Health Budgets (SIOPS) for the year 2005. Reported budgets were compared and correlated to the municipalities' geographic location. We conducted a cluster analysis to create more homogeneous groups according to health-related budget. The study showed a major variability among different regions and States, with varying degrees of municipal dependence on external funds. Although the large variability in sources may indicate multiple strategies for ensuring the necessary budget funds, the study suggests some barriers to public health funding in larger municipalities.