The present invention relates to a puncture resistant sealable vapour barrier sterilisation bag capable of withstanding a steam sterilisation process whilst providing an effective microbiological barrier having a first sealable opening suitable for receiving items to be sterilised and a second sealable opening adapted to couple to a sterilisation conduit. A third sealable opening may be provided in the bag to facilitate circulation within the bag via the second and third openings when the first opening is sealed. The bag forms the means for sterilising an article(s) solely within the plastic bag in conjunction with a sterilisation services supply device. The bag is preferably formed of plastics. Preferably a multilayer construction including a puncture resistant outer layer and a heat-sealable inner layer. The bag may include a covert marking technology and/or a readable unique identification code such as a tamper-resistant label applied to the bag to facilitate uniformity and traceability.