This research aims to understand the variables involved in the citizens' conduct of complaint regarding the status of urban sanitation. It analyzes 932 complaints received from citizens at Madrid City Hall. We wanted to check whether this complaint conduct is a type of proambiental behaviour and/or an expression of citizen participation. The methodology used mixes qualitative (interviews and categorization of information) and quantitative techniques. The results allow elaborating a diagnostic map of the cleaning problems. We also describe the characteristics of the complaint behaviour and the conformation of specific profiles of behaviour for every type of environmental problem identified. Concretely we analyzed what moves people to act, to what they attribute the cause of the problems, whom they believe the consequences affect, as well as the solutions raised. Finally, we reflect on the contribution this information makes to the study of proambiental and participative behaviours, as well as on the advantages of elaborating programs of environmental management that favour sustainable behaviours in public institutions.