•Strong positive attitudes towards MaaS are recognised in Madrid (Spain).•Four clusters of MaaS users are identified according to attitudinal and personality factors.•Low technology affinity and low openness to “new mobilities” are the main barriers for adopting MaaS.•MaaS-lovers seem the most likely to reduce their private car usage in favour of alternative modes. Mobility as a Service (MaaS) is expected to significantly change our mobility patterns. However, it is still not clear who will accept this new mobility paradigm and how it will affect travellers’ behaviours. In this study, we identify a set of attitudinal and personality factors relevant for MaaS adoption based on a survey comprising 1,000 respondents in the metropolitan area of Madrid (Spain). The results show strong positive attitudes towards MaaS after being validated through a structural equation model. The higher the percentage of multimodal travellers, the more they are open to “new mobilities”, the greater their technological capabilities and curiosity, and the lower their cost sensitivity, then the higher the adoption potential for MaaS. Our analysis reveals four clusters in terms of individuals’ intention to use MaaS technologies (technological car-followers, unimodal travellers, MaaS-lovers and active public-transport supporters). Motivated by a significant environmental sensibility, MaaS-lovers appear to be the most likely to reduce their private car usage in favour of alternative modes. Overall, we recognise two main barriers that can frustrate MaaS adoption: low technology affinity and low openness to sharing-mobility services. Policies that focus on these two aspects can encourage MaaS acceptance.