Trauma-informed care practices are associated with a culture of safety following traumatic experiences, including medical trauma. An interactive, web-based training package (‘Responsive CARE’) was developed for voluntary uptake by paediatric burns health professionals to increase staff knowledge about trauma-informed practice. This paper reports on a mixed methods process evaluation conducted alongside a preliminary effectiveness study of ‘Responsive CARE’. The process evaluation was conducted using The Consolidated Framework for Implementation Research (CFIR) and a logic model, to examine feasibility of both the intervention and implementation strategy. Health practitioners (including senior managers) delivering care to children and caregivers attending an outpatient burns service were eligible to enrol in ‘Responsive CARE’. Qualitative interview data and quantitative metadata were used to evaluate the implementation outcomes (adoption, acceptability, fidelity, feasibility and preliminary effectiveness). Children and caregivers attending an outpatient service for change of burn wound dressing or burn scar management during the 3-month control or 3-month intervention period were eligible to enrol in the effectiveness study. The impact on child pain and distress, as well as cost, was investigated using a pretest-posttest design. Thirteen (from anticipated 50 enrolled) health professionals (all female) with mean 10 years (SD=11) of experience with paediatric burns hospital-based outpatient care completed an average of 65% (range 36% to 88%) of available content. Twenty-five semi-structured interviews were completed with health practitioners (21 female) and with 14 caregivers (11 female). Four themes were identified as influencing feasibility and acceptability of the intervention: 1) Keeping a trauma-informed lens; 2) Ways of incorporating trauma-informed care; 3) Working within system constraints; and 4) Being trauma-informed. Preliminary effectiveness data included 177 participants (median age 2 years, and median total body surface area burn 1%). Causal assumptions within the logic model were unable to be fully tested, secondary to lower-than-expected adoption and fidelity. We found no significant difference for pain, distress and per-patient hospital care costs between groups (pre- and post-intervention). Future implementation strategies should include organizational support to keep a trauma-informed lens and to incorporate trauma-informed principles within a medical model of care. Despite efforts to co-design a staff education intervention and implementation approach focused on stakeholder engagement, adaptations are indicated to both the intervention and implementation strategies to promote uptake highlighting the complexity of changing clinician behaviours.