Adults with Asperger syndrome show persistent difficulties in social situations which psychosocial treatments may address. Despite the multiple studies focusing on social skills interventions, only some have focused specifically on problem-solving skills and have not targeted workplace adaptation training in the adult population. This study describes preliminary data from a group format manual-based intervention, the Interpersonal Problem-Solving for Workplace Adaptation Programme, aimed at improving the cognitive and metacognitive process of social problem-solving skills focusing on typical social situations in the workplace based on mediation as the main strategy. A total of 50 adults with Asperger syndrome received the programme and were compared with a control group of typical development. The feasibility and effectiveness of the treatment were explored. Participants were assessed at pre-treatment and post-treatment on a task of social problem-solving skills and two secondary measures of socialisation and work profile using self- and caregiver-report. Using a variety of methods, the results showed that scores were significantly higher at post-treatment in the social problem-solving task and socialisation skills based on reports by parents. Differences in comparison to the control group had decreased after treatment. The treatment was acceptable to families and subject adherence was high. The Interpersonal Problem-Solving for Workplace Adaptation Programme appears to be a feasible training programme.