The paper describes an indicator constructed to measure financial flows between local governments in Poland. These flows are considered as the measure of local governments’ cooperation and of the strength of functional connections crossing administrative boundaries. The purpose of this paper is to present the scale and the subject of financial transfers between local governments and the factors explaining the variation of local governments’ financial cooperation. The biggest financial transfers take place in functional urban areas, but only in terms of current expenditures. Transfers of investments expenditures are higher outside these areas and are characteristic of less affluent municipalities. The strongest associate function is to provide transportation services: both in terms of current expenditures and investments.