This Element reviews the evidence for three workplace conditions that matter for improving quality and safety in healthcare: staffing; psychological safety, teamwork, and speaking up; and staff health and well-being at work. The authors propose that these are environmental prerequisites for improvement. They examine the relationship between staff numbers and skills in delivering care and the attainment of quality of care and the ability to improve it. They present evidence for the importance of psychological safety, teamwork, and speaking up, noting that these are interrelated and critical for healthcare improvement. They present evidence of associations between staff well-being at work and patient outcomes. Finally, they suggest healthcare improvement should be embedded into the day-to-day work of frontline staff; adequate time and resources must be provided, with quality as the mainstay of professionals' work. Every day at every level, the working context must support the question 'how could we do this better?' This title is also available as Open Access on Cambridge Core.