Conference paper, International European Forum, Innsbruck, Austria, February 5-9, 2018. Pages 271-283 in proceedings published in this journal., The increasing impact due to urban population’s food supply causes a series of negative externalities related to food production, transformation and transportation. FAO and other institutions are trying to integrate traditional models of food supply with alternative ones like Urban and Peri-Urban Agriculture (UPA). Defining the drivers that motivate the participation in different types of UPA could be useful to plan more participated and effective UPA development policies. Barcelona (Spain) hosts a number of cases representing different declinations that UPA can assume. This work aims at describing the differences in terms of motivations to enter the various typologies of Urban Agriculture (UA) in Barcelona. Data were collected through semi-structured interviews to 4 groups of users representing 3 of the most widespread models of UA initiatives in Barcelona (Allotment Gardens, Community Gardens, Pla Buits.) The results showed that participation in UA is mainly motivated by relational aspects and knowledge exchange and differences exist among the various UA models. Political reasons are mostly influencing the Community Gardeners while Pla Buits users’ mains motivations are related to socialising and Allotment gardeners are mainly motivated by environmental aspects. Differences in the participants’ demographic characteristics also emerged. Better targeted public policies contents and communication strategies for UPA development can thus be derived by the results obtained; to this end, recommendations have been provided. Further research should broaden the range of case studies and the sample size, in order to provide a more effective and comprehensive tool for tailoring UPA developing strategies to different contexts.