Because of the increasing numbers of immunosuppressed patients and the general resurgence of mycobacterial infection, diagnostic bronchoalveolar lavage (BAL) using a fibreoptic bronchoscope is an important and frequent procedure. A contaminated bronchoscope may introduce spurious mycobacteria into specimens causing diagnostic confusion, infect the patient with mycobacteria, or be a vehicle for cross-infection. Bronchoscopes are difficult to disinfect adequately if they are not properly cleaned (which may include stripping down channel valves) or are damaged. Bronchoscope washers have also contributed to the problem when glutaraldehyde becomes too dilute or they become heavily contaminated with environmental mycobacteria. Future solutions to prevent contamination include the regular maintenance of bronchoscopes and washers, having adequate cleaning and disinfection protocols and ensuring that they are adhered to, improving bronchoscope and washer design, and developing alternative disinfectants or new ways of using current ones. All these will probably have considerable cost implications for hospitals.