Eosinophilia is a common finding in returning travellers, migrants and other travelling groups. In this setting, it often indicates an underlying helminth infection. Infections associated with eosinophilia are frequently either asymptomatic or associated with non-specific symptoms but some can cause severe disease. Here the British Infection Association guidelines group has comprehensively reviewed and updated the UK recommendations for the investigation and management of eosinophilia in returning travellers, migrants and other relevant groups, first published in 2010.