Urban 'third places' foster informal interactions and face-to-face contact that is critical to the development of new innovations and start-up businesses. Our research utilises extensive microdata in combination with telephone interviews with over 200 start-up companies in Stockholm, Sweden. Our findings indicate that access to third places has a significant impact on the number of new high-tech start-ups (both by entrepreneur place of residence and work) in their vicinity. This suggests that third places play a demonstrable role in innovation and economic growth.