Four commercially available endoscope washing machines (Pyser System 83, Wolf Fiberscope Disinfector, Olympus EW20, Keymed Auto-Disinfector) were evaluated. In most cases the machines were expensive, immobile and noisy, and could only wash one endoscope per cycle. Daily use involved repetitive chores and contact with glutaraldehyde. Disinfection procedures were flawed; no machine auto-disinfected adequately. In conclusion, these machines are unsatisfactory and represent a potential source of serious infection.