There is nothing inherently wrong about museums purchasing specimens from commercial dealers who act honestly and in good faith. Indeed, a significant amount of the taxonomically important material in the UK's great public collections has been acquired in this way. Doing business with the trade does, however, carry risks, and there are many ways in which the unwary curator can be ripped off by an unscrupulous dealer. Apart from fakes and forgeries, the most pernicious and damaging aspect of the trade is in illicit material. Museums should respect the laws of countries which seek to protect fossils as part of their cultural patrimony. This ethic is enshrined in international convention and in the ethical codes that apply to UK museums both at an individual and institutional level, through the UK's Registration scheme. The UK is about to become signatory to the 1970 UNESCO Convention, which outlaws the international illicit trade in cultural property, and will create a new law to criminalise such activity. This paper argues the case for accepting UNESCO's inclusion of fossils in the definition of cultural property. The more relaxed ethic of some academic palaeontologists compared with the ethical standards of mainstream geological curators in the UK should be addressed by drafting a protocol, whose standards should be developed in consultation between curators, academics, and reputable representatives of the trade and third world countries from which most illicitly traded fossils originate.