Objective: We present prevalence estimates and secular trends of stunting, wasting, underweight, and anaemia among children under five years of age, and low birth weight (LBW) over the period 1985–2019 in West Africa (WA). Design: Analysis of Demographic and Health Survey (DHS) and World Bank data. DerSimonian–Laird random-effect model with the Knapp–Hartung adjustment to the standard error was used to derive overall prevalence estimates. We used fixed-effect ordinary least square regression models with cluster robust standard error to conduct time trends analyses. Setting: West Africa Participants: Children aged 0 to 59 months Results: Three distinct periods (1986-1990, 1993-1996 and 1997-2000) of sharp increases in prevalence of all outcomes was observed. After the year 2000, prevalence of all outcomes except LBW started to decline with some fluctuations. LBW prevalence showed a steady increase after 2000. We observed a decline in prevalence of stunting (β=-0.20%; 95%CI: -0.43%, 0.03%), log-wasting (β=-0.02%; 95%CI: -0.02%, -0.01%), log-underweight (β=-0.02%; 95%CI: -0.03%, -0.01%) and anemia (β=-0.44; 95%CI: -0.55%, -0.34%), and an increase in LBW (β=0.06%; 95% CI: -0.10%, 0.22%) in WA over the period. Pooled prevalence of stunting, wasting, underweight, anemia and LBW in WA for the period 1985-2019 was 26.1%, 16.4%, 22.7%, 76.2% and 11.3%, respectively. Conclusions: Child undernutrition prevalence varied greatly between countries and the year cohorts. We observed marginal reductions in prevalence of all outcomes except anemia where the reductions were quite striking and LBW where an increase was noted. There is the need for more rigorous and sustained targeted interventions in WA.