The aim of this observational longitudinal cohort study was to describe relationships over time between degrees of stress of conscience, perceptions of conscience, burnout scores and assessments of person-centred climate and social support among healthcare personnel working in municipal care of older people. This study was performed among registered nurses and nurse assistants (n = 488). Data were collected on two occasions. Results show that perceiving one’s conscience as a burden, having feelings of emotional exhaustion and depersonalization and noticing disturbing conflicts between co-workers were positively associated with stress of conscience. No significant changes were observed during the year under study, but degrees of stress of conscience and burnout scores were higher than in previous studies, suggesting that downsizing and increased workloads can negatively affect healthcare personnel. Following and expressing one’s conscience in one’s work, and perceiving social support from superiors are of importance in buffering the effects of stress of conscience.