This study aimed to identify positive behavioural changes that people may make as a result of negotiating the aftermath of a traumatic experience, thereby extending the current cognitive model of posttraumatic growth (PTG). It was hypothesised that significant others would corroborate survivors' cognitive and behavioural reports of PTG. The sample comprised 176 participants: 88 trauma survivors and 88 significant others. University students accounted for 64%; 36% were from the broader community. Approximately one third were men. All participants completed the Posttraumatic Growth Inventory (PTGI) and open-ended questions regarding behavioural changes. The PTGI scores of the survivors were corroborated by their significant others with only the Appreciation of Life factor of the PTGI differing between the 2 groups (e.g., total PTGI scores between groups explained 33% of variance). Nearly all of the survivors also reported positive changes in their behaviour; these changes were also corroborated by the significant others. Results provide validation of the PTG construct and the PTGI as an instrument of measurement. Findings may also influence therapeutic practice by pointing to the potential usefulness of corroborating others in the recovery and growth process.