The WHO publication “Surveillance, case investigation and contact tracing for mpox: interim guidance” provides updated global technical guidance on monitoring and responding to mpox (formerly known as monkeypox). It explains how countries should conduct surveillance to detect new outbreaks, carry out case investigation including clinical assessment and lab specimen collection, and perform contact tracing to monitor people exposed to confirmed or probable cases in order to stop transmission and protect at-risk groups. The guidance includes practical recommendations for how long contacts should be monitored (e.g., daily for 21 days without requiring quarantine if symptom-free) and advising good hygiene and reduced exposure risk during the monitoring period. This interim guidance is intended to support public health authorities worldwide in strengthening mpox outbreak detection, response, and reporting.