Investigations of mood and workload in health care settings have focussed primarily on nurses and junior doctors. Given the critical shortfall in the Australian midwifery workforce, and the specialised nature of midwifery as an occupation, it is important to understand how mood and workload are experienced by midwives. Twenty midwives (18F, 2M) in an Australian metropolitan hospital completed logbooks assessing daily fluctuations in subjective mood and workload. Participants also provided information about history of psychopathology and sleep quality. Results revealed that midwives were relatively stable in terms of mood but did experience increased fear and decreased happiness when at work. Further, workload factors significantly predicted mood at work. Specifically, when participants felt that their work was more demanding and frustrating and required more effort, or when they felt that they could not accomplish all that was expected, mood was negatively influenced. This supports the connection between workload and negative mood change in healthcare. Given the potential for mood to influence a multitude of functions relevant to safety, performance and psychosocial wellbeing it is important to understand the factors which influence mood, particularly in light of the current shortfall in the Australian healthcare workforce.