There is an urgent need to find strategies to promote positive mental health in the workplace. The current study presents outcomes of a pilot trial of the Promoting Adult Resilience (PAR) program, an innovative mental health promotion program, which is conducted in the workplace over 11 weekly sessions. The PAR program is a strengths-based resilience-building program that integrates interpersonal and cognitive–behaviour therapy (CBT) perspectives. Pre-, post- and follow-up measures on 20 PAR participants from a resource-sector company were compared with a non-intervention-matched comparison group. At follow-up, the PAR group had maintained significant post-test improvements in coping self-efficacy and lower levels of stress and depression, and reported greater work-life fit than the comparison group. The program appeared to be ecologically valid and treatment integrity was maintained. Process evaluations of PAR program showed that skills were rated highly and widely used in everyday life at both post and follow-up measurement times.