Candida parapsilosis was detected in environmental swabs and batches of total parenteral nutrition (TPN) products after routine monitoring. The isolates were analysed using randomly amplified polymorphic DNA (RAPD) to determine clonality and establish the most likely source of contamination. Of 20 isolates analysed, 18 were indistinguishable clonally and were found to be associated with particular work stations. The application of regular testing using a system such as the BacT/Alert, and molecular studies for epidemiological analysis, is of benefit to producers of medical products such as TPN to ensure patient safety.