Individuals who are high in trait mindfulness are less stressed at work, better adjusted, and healthier than individuals who are low in this trait (Allen et al., 2015; Irving et al., 2009; Lomas et al., 2017) [1-3]. To date, trait mindfulness has not been considered within current, empirically supported, workplace stress models. Therefore, the present study explored if trait mindfulness, when used in conjunction with the Effort-Reward Imbalance model (Siegrist, 1996) (ERI ) better explains the links between workplace stress and non-adaptive physiological arousal. Across 2 timepoints (Summer-Winter) direct-care workers completed job stress (ERI), trait mindfulness, and health questionnaires and provided morning saliva samples to assess physiological indices of stress and ill-health. Compared across timepoints, changes in ERI and overcommitment were not associated with changes in the cortisol awakening response, salivary alpha amylase awakening response or secretory immunoglobulin A (sIgA). However, higher trait mindfulness was associated with increased sIgA. Potentially, trait mindfulness may act as a protective factor against ensuing ill-health and further, may be useful in better understanding the underlying mechanisms of the workplace stress-ill-health relationship.