In 2015 10 Iberian lynxes Lynx pardinus were released in south-eastern Portugal, within the framework of a Spanish–Portuguese reintroduction project. We examined each individual's use of space and social interactions during the first year after their release. Lynxes were selected for reintroduction according to behavioural, genetic and health criteria and fitted with collars with VHF and global positioning systems. Both males and females went through an exploratory phase that lasted 65–105 days. The lynxes did not exhibit any movement directionality from the release site during the exploratory period. During August–December 2015 a stable nucleus comprising seven individuals (four males, three females) was established south-west of the release enclosure. Although the males had a slightly larger mean home range (11.18 ± SE 1.36 km2) than females (9.87 ± SE 8.71 km2), the difference was not significant. The knowledge obtained during the first year of the lynx reintroduction project in Portugal is critical to support the future of this reintroduction strategy. Our results suggest that once the soft release technique is no longer possible because of logistical constraints on the construction of more enclosures, new individuals should be released in unoccupied areas surrounded by occupied territories. This will promote strong social ties to the resident population and prevent lynx dispersal.