A cluster of ten nosocomial eye infections occurred in three intensive-care units during an 18-month period. Nine of the ten patients were intubated, all were obtunded, and all had copious sputum production. The bacteria isolated from the patients' sputum samples and from the eyes were identical in nine cases. Pseudomonas aeruginosa caused six of the infections, including all those with complications (three corneal ulcers, two hypopyon, one opaque cornea, two corneal rupture). Three patients lost their sight. Only the left eye was infected in nine cases. In a prospective study of bacterial dispersion during tracheal suctioning of twenty intubated patients, patients with copious secretions had significantly higher bacterial colony counts on settle plates than those without. Colony counts were higher on the side opposite to the hand the nurse used to withdraw the catheter than on the same side. Nurses tended to withdraw the catheter diagonally across the patient's face, which may explain the selective involvement of the left eye.