Introduction: Occupation-based groups are used in inpatient rehabilitation to enhance delivery and intensity of intervention; however, little research is available to understand their effectiveness. The aim of this study was to examine the process of an occupation-based group to understand mechanisms and success factors. Methods: A mixed methods process evaluation using an evidence-based framework guided implementation and analysis. Participants were those involved in the ‘LifeSkills’ group run daily in an adult inpatient general rehabilitation ward. Quantitative administrative data, goal achievement outcome measures, group observations and qualitative semistructured interviews were conducted. Results: Thirty participants were recruited. Factors for success included consistency in group structure and support, using meaningful practise opportunities and facilitating a real-world experience. There was no significant relationship between patient outcomes and dose of training or patient demographics. Conclusion: This evaluation contributes to a growing body of evidence for incorporating occupation-based approaches into rehabilitation and offers insights into practice implementation.