A study on ventilator-associated pneumonia was done in the I.C.U., Nan Hospital from April 1991 to March 1992. Of the 536 patients, 40 had pneumonia (7.5%). One half of the cases with pneumonia were on mechanical ventilation for 3-7 days. The incidence rate of pneumonia was 17.5, 6.5, 2.5 and 0 per cent in paediatric, medical, surgical and gynaecologic patients. Nine patients died of pneumonia. Low birth weight was the commonest predisposing factor of death along with prolonged ventilatory support and resistant bacteria. Breaching of aseptic and nursing care techniques was also observed.