Ventilation in healthcare facilities is important to ensure the comfort of patients and staff, the removal of noxious fumes or potentially toxic gases and the prevention and control of infection (IPC). Traditionally, most areas within hospitals are naturally ventilated via doors and windows, with the opening of these increasing airflows. Artificial ventilation is, however, required in the operating theatre (OT), in air-controlled ventilation rooms (ACVR) and in other selected areas such as in laboratories and pharmacy. The evidence for the effectiveness and value of ventilation in preventing infection arising in the OT is variable and questions have been raised about the need for ultraclean ventilation for prosthetic joint surgery. The increasing numbers of vulnerable and immunosuppressed patients in many acute hospitals has increased the call for more ACVR. The recent COVID-19 pandemic has caused us to re-examine our understanding of how respiratory viruses are spread and simple categorisation as spread by droplet or aerosol may be too simplistic. While simple measures such as opening doors and windows where possible can assist in IPC measures to prevent the spread of microbes by air, a review of ventilation requirements in healthcare facilities is required to address and anticipate future needs. Some additional ACVR are required but also a review of hospital design is necessary with more single rooms. We also need to consider the possible utilisation of alternative/new technologies on financial and environmental grounds.