Since March 2016 China has required a mosquito eradication certificate for cargoes originating from countries at risk from the Zika virus. At present there are around 68 countries on the ‘at risk’ list, including the US which is China’s largest trading partner. Recent reports have raised concerns that the need for these certificates can cause delays at the ports. To avoid delays, the cargo can be fumigated at the port of origin and the necessary certificate obtained. The delays appear to be where cargoes arrive without the certificates and are fumigated in the Chinese port. In the past, the certificates had to be obtained from the port of origin but it now appears that the fumigation can be carried out on arrival in China. Although the costs of fumigation may be lower in Chinese ports, there may be delays while the fumigation is carried out. To avoid these delays, Members trading between Zika-infected areas and China are advised to check the regulations with their local agents or local correspondents and make sure that the necessary fumigation is carried out, either in advance or on arrival.