The overall objective of continual global surveillance for human infection with avian influenza A(H5) viruses is to detect and characterize any influenza A(H5) viruses infecting humans in order to: (1) promptly trigger public health control and response actions, (2) assess the trends of such infections and the public health risks posed (including the risk of a pandemic); and (3) inform global pandemic preparedness activities. This document summarizes the WHO implementation guidance on surveillance for human infection with influenza A(H5) viruses.