The aim of this study was to assess nurses' performance related to control and prevention of nosocomial respiratory infection in artificially ventilated patients and to estimate incidence and the causative microorganisms of such infection. The study was conducted on 30 ventilated patients and 30 nurses who were responsible for their care. An observation checklist was used to assess nurses' practices regarding daily care activities, ventilator decontamination, use of universal infection control measures and maintenance of the patients' care environment. A second sheet was developed to estimate incidence of nosocomial respiratory infection and identification of the causative microorganisms. A third sheet was designed to help in daily assessment of the patient's health condition. The study revealed a high incidence of nosocomial respiratory infections (83.3%) and pseudomonas was the causative agents in more than one-fourth of the cases. Moreover, nurses' infection control practices were inadequate.