Klebsiella pneumoniae serotype K28 was cultured from six patients over 5 weeks in a general Intensive Care Unit. Colonized condensate in the ventilator expiratory water traps was the probable source of the organism, and hand carriage the vehicle of transmission. Although the cross-infection hazard of ventilator tubing condensate is recognized, there is no report in the literature of an outbreak caused by such fluid. Ventilator tubing condensate should be viewed as contaminated clinical waste and dealt with accordingly.