This document provides interim recommendations for the surveillance of Zika virus infection, microcephaly and Guillain-Barré syndrome, in four different contexts and describes reporting requirements to WHO. Transmission refers to vector-borne transmission, unless specified differently. Autochthonous infection is considered to be an infection acquired in-country, i.e. among patients with no history of travel during the incubation period or who have travelled exclusively to non-affected areas during the incubation period. This document does not provide guidance on laboratory investigation or vector surveillance.