Objectives <p>The purpose of this study was to develop a behavioural marker system (BMS) to measure observable mindful caregiving behaviours among caregivers of individuals with developmental disabilities, such as parents or direct support professionals.</p> Method <p>Eight mindfulness experts participated in semi-structured interviews designed to evoke descriptions of mindful caregiving behaviours. Using a template analysis, behaviours identified during the interviews were organized into a hierarchical framework based on a two-component model of mindfulness. The analysis was iterative, involving repeated coding and template refinement informed by new data, inter-rater reliability measures, member checking, and memo writing. Based on the resulting framework, a BMS for mindful care was developed.</p> Results <p>Thirty-three unique observable mindful caregiving behaviours were identified: 24 positive indicators and 12 negative indicators. These behaviours reflect: (1) the caregiver’s ability to maintain attention on relevant features of the immediate caregiving experience, including the ambient environment, care recipient, and caregiver, while minimizing attention on irrelevant features; and (2) responses to challenging experiences that are either consistent or inconsistent with an orientation towards curiosity, openness, and acceptance. The BMS was formatted as a data sheet utilizing momentary time sampling and partial interval recording strategies to measure the occurrence of each behaviour during caregiving interactions.</p> Conclusions <p>The BMS for mindful care represents a novel tool for measuring mindful caregiving behaviours. It can be used to evaluate the impact of caregiver mindfulness training, enabling organizations to identify effective programs, improve caregiving quality, and support better care outcomes for individuals with developmental disabilities.</p>