Sensory modulation (SM) and trauma-informed-care (TIC) are therapeutic strategies which can help avoid incidents of aggression and thus reduce the use of restrictive interventions in mental health settings. In order to educate mental health nurses and allied health professionals in these strategies, a train-the-trainer intervention was developed and delivered to 19 area mental health services as a statewide, government funded program. This descriptive qualitative study evaluated the effectiveness of the intervention to: a) transfer knowledge; and, b) translate knowledge into practice. Semi-structured interviews were conducted with senior staff (n = 21); focus group discussions with trainees (n = 10); and, a paired in-depth interview with master trainers (n = 2). In total, 170 trainees attended two day train-the-trainer sessions. Many trainees were not in education roles. Most services facilitated further knowledge transfer to end-user clinicians, though training materials were often adapted. End-users' responses to SM/TIC training were generally positive to the training, but some were resistant to the change in practice. Limited anecdotal evidence of translation of SM/TIC into practice was provided. Ongoing support is required to maintain a focus on SM and TIC, sustain and encourage further knowledge transfer and translation, and assess the impact on consumer and staff health outcomes.