From 28 March to 3 April 2025, one new case of human infection with avian influenza A(H5N1) virus was reported to WHO in the Western Pacific Region. The case is a 3-year-old male from Kratie Province, Cambodia, with onset of symptoms on 18 March 2025. He was hospitalized on 21 March and passed away on 23 March 2025. The case had exposure to dead chickens at his house.