Introduction: The prevalence of wasting in the Philippines has not significantly declined in recent years, from 5.7% in 2018-2019 to 5.5% in 2021. This study examined agerelated patterns of wasting and stunting across socio-demographic groups and identified socioeconomic and demographic factors associated with wasting among Filipino children under five years. Methods: The study utilised cross-sectional population-based surveys conducted in 2018 and 2019. Descriptive statistics and multiple logistic regression analysis were used to analyse data from 26,416 under-five children. Results: Wasting was highest at birth (8.2%) and peaked at 12-17 months (8.4%) before declining to 5.1% by age two. In contrast, stunting was lower at birth (10.2%), increasing sharply to 29.4% at 12-17 months and 38.3% at 18–23 months before slightly decreasing to 32.4% at two years old. Boys, children in rural areas, and those from poor households were more affected by wasting and stunting. Multivariate analysis showed increased odds of wasting in children whose mothers were thin (BMI <18.5 kg/m2) (AOR=1.4, p=0.013), short (<150 cm) (AOR=1.3, p=0.013), and less educated (AOR=1.5, p<0.001); for children over two, only mothers who were thin (AOR=1.6, p=0.006). Rural-urban differences were observed, with maternal and child factors strongly associated with wasting in rural areas, and maternal and household factors in urban areas. Conclusion: The findings underscore importance of strengthening interventions during the first 1,000 days of life. Context-specific strategies addressing maternal nutrition, education, and household conditions, while accounting for rural–urban disparities, are essential to prevent wasting and stunting among Filipino children.