Introduction and objective: Most studies focus on mothers’ reactions to their child’s long‑term hospitalisation and the consequences of the illness. Much less attention has been paid to mothers’ reactions during the initial phase of hospitalisation, particularly in cases of short hospital stays. Previous research has also overlooked emotional states such as feelings of hurt, a sense of injustice, or resentment, which may contribute to the experience of ressentiment. This study examines the determinants of ressentiment in mothers of children admitted to a paediatric ward, with particular consideration of short hospital stays. Materials and methods: The study involved 135 mothers of children hospitalised in a paediatric ward. Data were collected using a set of questionnaires, including the Ressentiment Questionnaire, the General Self‑Efficacy Scale, and the Courtauld Emotional Control Scale. Results: The level of ressentiment experienced by the mother correlated with the child’s age and the mother’s subjective assessment of the child’s health. A positive correlation was found between ressentiment and anger control as well as anxiety levels. A negative correlation was observed between ressentiment and an emotion‑focused coping style. Additional associations were identified between ressentiment, the tendency to suppress anger, and mothers’ perceived self‑efficacy in dealing with difficult situations. Conclusions: Mothers of younger children tend to suppress sadness, feelings of hurt, and resentment, experiencing higher levels of ressentiment, and should therefore receive additional support. Interventions such as psychological counselling and therapeutic assistance may help reduce negative emotions, diminish anger, and prevent the intensification of depressive symptoms. Strengthening mothers’ self‑efficacy may contribute to lowering the level of ressentiment. These conclusions highlight areas for intervention and emphasise the mother’s role in the child’s active treatment process, which fosters a sense of agency and enhances self‑efficacy.