Duque, Mariana PerezAlburhomyAhmed, AliSaleh, YousefWolz, AnjaAbecasis, Ana B.Saad Duque, Neil J.Salje, HenrikGil-Cuesta, JulitaRobays, JoVeicht, RaphaelAlazab, Saleem2025-07-312025-07-312025-072767-3375PURE: 123190957PURE UUID: 4a94cdfb-d7dd-433f-9f89-59f0cbe94003Scopus: 105011212535WOS: 001527608700001PubMed: 40644489PubMedCentral: PMC12250524http://hdl.handle.net/10362/185854Funding Information: Médecins Sans Frontières (MSF) provided support in the form of salaries for MPD, Ab.A, AA, YS, AW, JGC, JR, RV, SA. MSF programmatic funding covered all costs associated with the survey which was conducted for operational purposes. MSF was involved in the study design, data collection and analysis, decision to publish, and preparation of the manuscript. AA is funded through funds from Fundação para a Ciência e Tecnologia (FCT) to GHTM-UID/04413/2020 and LA-REAL-LA/P/0117/2020. MPD is currently funded by Gates Cambridge Trust (OPP1144), which had no role in the study and decision to publish. Publisher Copyright: © 2025 Perez Duque et al.The ongoing conflict in Yemen, which began in 2014, has led to one of the world’s most severe humanitarian crises. The Hudaydah region, located on the Red Sea coast and home to the country’s second-largest port, is critical for the delivery of food and medical supplies. We conducted a two-stage cluster randomised survey to estimate the prevalence of acute malnutrition among children and pregnant and lactating women (PLW). We estimated the prevalence of household food insecurity and quantified death rates. During February-March 2021, acute malnutrition prevalence was 14.1%(95%CI: 12.2-16.2) among children aged 6–59 months, with 4.0%(95%CI: 3.3-4.9) severely malnourished. 43% of malnourished children were not in a nutritional programme. Acute malnutrition among PLW was 25.7%(95%CI: 23.0-28.6). We estimated 54%(95%CI: 44–63) of households were food insecure, 22%(95%CI: 15–31) severely. Crude and under-five death rates were below humanitarian thresholds. More than half of the children reported sickness in the last 14 days, and this proportion was higher among the malnourished.825147engCritical Care and Intensive Care MedicinePublic Health, Environmental and Occupational HealthSDG 2 - Zero HungerSDG 3 - Good Health and Well-beingjournal article10.1371/journal.pgph.0004331https://www.scopus.com/pages/publications/105011212535