Purpose – This paper concerns the adoption of the industrial symbiosis at the urban level as a tool to improve their environmental sustainability. Accordingly, urban wastes can be valued in new products or energy, able to reduce the amount of wastes landfilled and the amount of inputs purchased from external sources. In particular, we focus on small cities. We are interested to identify which urban features are able to influence the amount of produced urban wastes that can become inputs for processes of industrial symbiosis. As urban features, we take into account household features and the economic and productive structure of cities. Design/methodology/approach – We adopted a multiple case study approach for six small municipalities located in the Alto Bradano Area (South Italy). For each municipality, we collected data of produced urban wastes which can be used for symbiotic processes. In particular, we analyze the influence of two kinds of urban features: i) socio-economic parameters reflecting household features; ii) the area of non-residential activities, which we consider a proxy for the economic and productive structure of cities. Originality/value – This paper spreads new light on the industrial symbiosis application at the urban level. Differently from previous studies about waste production, we focused on small cities and we analyzed the effect of the economic and productive structure of cities on the amount of urban wastes. The value of this work lies in the identification of which urban features should be considered in evaluating the implementation of symbiotic projects at the urban level. Practical implications – This study provides interesting managerial implications about the industrial symbiosis approach at the urban level. In particular, the present work can offer a useful guide to define the symbiotic loops that could be significant for a city.