In Papua New Guinea (PNG), the most common cause of death among children under 5 years of age is pneumonia. Children with severe pneumonia need antibiotics and oxygen but oxygen shortages are common owing to the cost and complex logistics of transporting it in cylinders. Detection of hypoxaemia using clinical signs can be difficult, especially in highly pigmented children in whom cyanosis is difficult to recognise. Pulse oximetry is the most reliable, non-invasive way of detecting hypoxaemia. However, most hospitals in PNG do not have pulse oximetry. We proposed that the installation of a reliable, sufficient and cheap supply of oxygen in hospitals coupled with the use of pulse oximetry would make a significant difference to child survival rates in PNG. Oxygen concentrators, which extract oxygen from ambient air, were installed in the children's wards of five hospitals during 2005. Pulse oximeters were also introduced to enable better detection of hypoxaemia. This paper describes the technical aspects of this programme: the equipment used and the rationale behind choosing it, the installation, commissioning and testing processes. The ongoing training of clinical and engineering staff as well as two follow-up evaluations are described.