Reintroductions involve the relocation of animals into their historical range following extinction or extirpation. In this context, individuals with certain personalities may be more successful than others. For example, proactive individuals may dominate by being bolder, exploratory and more willing to take risks in familiar, stable environments (i.e. the source environment). Reactive personalities, in contrast, may thrive in novel, unstable environments (i.e. the release site) by being vigilant and risk averse. In addition, an individual's ability to adjust its behaviours over time (plasticity, or responsiveness) can play a pivotal role in determining postrelease performance. There is uncertainty, however, surrounding which behavioural measures translate to reintroduction success. We conducted behavioural assays and postrelease monitoring for eastern quolls, Dasyurus viverrinus, to determine whether behavioural measures (e.g. latency to emerge, time spent vigilant) could predict postrelease survival and dispersal in a fenced sanctuary. Using the ‘behavioural reaction norm’ approach, we found that personality derived from time spent exposed or vigilant during the assays had significant associations with postrelease den sharing and home range, while plasticity derived from latency (i.e. time delay) to reach food had a significant association with mean distance between consecutive dens. We recommend that proactive and rigid founders be preferred for initial trial reintroductions, and that reactive and plastic founders be used to supplement the population in later translocations. Our study demonstrates that, by including novelty, innovative behavioural assays offer significant value as a conservation tool to provide the fastest pathway to reintroduction success.