Treball Final de Grau en Finances i Comptabilitat. Codi: FC1049. Curs acadèmic 2013-2014 This work will study the socio-demographic determinants, political, budgetary and economic, that affect the transparency of local entities. To perform the study, we have chosen the transparency index data for the 110 largest municipalities of Spain, in 2012 has been chosen from the information offered by the website of the organization Transparency International Spain. The results indicate that the budget imbalance and population, influence an increase in the level of transparency. On the contrary, factors such as debt per capita, unemployment and provincial capital, affect a decrease in the level of transparency. In addition, through the evolution of the global index it has been possible to conclude that legislation on transparency and the organizational Transparency International Spain, have helped to stimulate the disclosure of the information from local governments.