This paper presents a first analysis on local electronic participatory experiences in Catalonia. The analysis is based on a database constructed and collected by the authors. The paper carries out an explanatory analysis of local initiatives in eparticipation and off line participation taking into account political variables (usually not considered in this kind of analysis) but also classical socio-economic variables that characterise municipalities. Hence, we add a quantitative analysis to the numerous case studies on local e-participation experiences. We have chosen Catalonia because is one of the European regions with more initiatives and one that has enjoyed considerable local governmental support to citizen participation initiatives since the 80s. The paper offers a characterisation of these experiences and a first explanatory analysis, considering: i) the institutional context in which these experiences are embedded, ii) the characteristics of the citizen participation processes and mechanisms on-line, and iii) a set of explanatory variables composed by the population size, the political adscription of the mayor, the electoral abstention rate, age, income and level of education in the municipality. The model that we present is explanatory for the municipalities with more than 20,000 inhabitants but it is not for the fewer than 20,000 inhabitants. Actually, the number of participatory activities developed by these last municipalities is very low. Among all the variables, population size becomes the most influential variable. Political variables such as political party of the mayor and the local abstention rate have a certain influence but that have to be controlled by population size.