The aim of this study was to identify possible factors associated with the marked geographical variation in supply of public dental services in Norway. We identified three sources for this uneven distribution: differences in dental care needs, differences in revenue levels between counties, and differences in the party composition of the county councils. Analyses were undertaken to ascertain whether these factors were related to the variation in the number of man-labor years of public dental officers. The analyses were performed on a set of data from Norwegian counties for the period 1985-92. There was an association between the number of man-labor years of public dental officers and our indicators of dental care needs, county revenue, and party composition of the county councils. Our findings are encouraging, as they indicate that the county councils seemed to respond to the dental care needs of the local population. On the other hand, there were inequalities in supply of public dental services that were due to differences in revenue between counties. From an equity point of view, this inequality is undesirable. The inequality could most likely be reduced by decreasing the variation in revenue between counties. Differences in party composition of the county councils had only a small effect on the geographical variation in the number of man-labor years of public dental officers.