This document provides interim guidance for clinicians, laboratories, health workers, public health officials and other stakeholders involved in the diagnosis and care of patients with suspected or confirmed mpox. This is an updated version of the interim guidance on Laboratory testing for the monkeypox virus and supersedes the one published on 23 May 2022. This version includes updated recommendations on alternative specimen types for testing, considerations for reducing risks of infection during specimen collection, and updated considerations around monkeypox virus (MPXV) versus orthopoxvirus (OPXV) laboratory confirmation. This version is in alignment with other updated interim guidance documents published by WHO since May 2022.