In recent years there has been a growing demand on the part of citizens and society to access public information and for greater information transparency in local government to increase public accountability. This claim is motivated mainly by the need to reduce corruption and abuses of power in these times of economic and social crisis. The purpose of this paper is to analyse the evolution of the information transparency to citizens and society, in the largest Spanish municipalities during the period of 2008-2012. In addition, we will analyse the economic and political factors that affect the level of transparency on the part of local authorities. The methodology is based on the ranking on International Transparency in Spain. The analysis draws on a descriptive and multivariate difference analysis.