Biocompatibility aspects of urinary catheters have been recognized by clinicians during the 1980's. After multiple reports of severe urethral damage caused by latex catheters, a series of investigations revealed that toxic substances added to the catheters during the manufacturing process can leak from the devices in situ and cause urethritis developing severe urethral strictures. Consequently, most manufacturers have improved their catheters, but there are still some catheters of inferior quality on the market. Quality is dependent on the biocompatibility testing methods. Cell culture tests are recommended, but there are no common standards regarding these. British Standards Institution has been the first in Europe to adopt toxicity limits for a cell culture test, but those are not acceptable. It is a task for the standardization committees working for the European Community to create adequate biocompatibility testing standards with clinically relevant toxicity limits. If this is not done, the use of latex catheters should be abandoned as potentially harmful devices.