This study assesses the prevalence and correlates of anemia among adolescents living in the war-affected region of Hodeida in Yemen. A secondary objective was to examine the effect of a nutrition education intervention on hemoglobin levels among anemic adolescents. A cross-sectional study was conducted on a random sample of adolescents aged 15–19 years in Hodeida (n = 400). A questionnaire was administered to inquire about demographic, socioeconomic, lifestyle and clinical characteristics. Capillary blood was obtained, anthropometric characteristics were measured and stool samples were collected. As for the secondary objective, anemic adolescents were randomly assigned to an intervention group (nutrition education and iron supplementation) and a control group (iron supplements only). The prevalence of anemia was 37.8%. Female gender, khat chewing, excessive menstruation, and experiencing headaches, fatigue, or dizziness were independent predictors of anemia. In contrast, adolescents who attended private schools, and reported snack consumption or handwashing had a significantly lower risk of anemia. A sample of 116 adolescents participated in the intervention (3 months). Hemoglobin levels were significantly higher in the intervention group compared to the control. Our findings contribute to the identification of high-risk groups that should be targeted by context-specific interventions. The implemented multicomponent intervention may serve as a prototype for larger-scale preventive programs.