Background: The surge in the development of social robots gives rise to an increased need for systematic methods of assessing attitudes towards robots. Aim: This study presents the development of a questionnaire for assessing attitudinal stance towards social robots: the ASOR. Methods: The 37-item ASOR questionnaire was developed by a task-force with members from different disciplines. It was founded on theoretical considerations of how social robots could influence five different aspects of relatedness. Results: Three hundred thirty-nine people responded to the (...) survey. Factor analysis of the ASOR yielded a three-factor solution consisting of a total of 25 items: “ascription of mental capacities”, “ascription of socio-practical capacities”, and “ascription of socio-moral status”. This data was further triangulated with data from interviews (n = 10). Conclusion: the ASOR allows for assessment of three distinct facets of ascription of capacities to social robots and offers a new type of assessment of attitudes towards social robots. It appeared that ASOR not only assesses ascription of capacities to social robots but it also gauged overall positive attitudes towards social robots. (shrink)