Moving in time with others is a central characteristic of social life and has been shown to promote a host of social-cognitive attunements (e.g., person memory, affiliation, prosociality) for those involved. Less attention has been paid, however, to how the effects of coordination can serve higher-order goal-directed social behaviour. Here we explored whether interpersonal synchrony impacts performance on a collaborative problem-solving task. One hundred and ninety two participants completed a short movement exercise in pairs whereby coordination mode was manipulated (in-phase synchrony, asynchrony, control). Each pair then jointly discussed a problem-solving exercise while the degree to which coordination spontaneously emerged was assessed. The results revealed that collaboration was more effective following in-phase coordination. Of theoretical significance, both instructed and spontaneous synchrony were associated with better performance, with the short-term history of each dyad shaping precisely when coordination was functional. Overall, the synchronization of body movements appears to support effective collaboration.