Five widely used neonatal face masks were tested on 44 babies for their efficiency in terms of degree of leakage and ease of cleaning. Leakage was measured indirectly. The mean peak pressure of ten breaths when babies were ventilated from a respirator via a mask was recorded; a low pressure was taken to indicate leakage. A triangular moulded rubber mask ('Rendell-Baker') leaked most and a circular silicone rubber mask ('Laerdal') leaked least. The ease of cleaning the masks was measured as the amount of bacteria removed from contaminated masks by wiping them with 70% ethanol. The Laerdal mask was significantly more effectively cleaned than the others. It is also the only one of the masks tested that can be boiled and autoclaved.