OBJECTIVE: This study was conducted to evaluate the causal analysis of undernutrition among adolescents in the context of the agrarian community of North-West Ethiopia. DESIGN: A community-based case-control study was conducted among 149 cases and 297 control adolescents. SETTING: Agrarian communities of North-West Ethiopia. PARTICIPANTS: Adolescents aged 10-19 years, who reside in a randomly selected study setting. OUTCOME MEASURES: The stunting and thinness nutritional status of adolescents was determined using the WHO AnthroPlus 2010 software. A general structural equation modelling approach was used to determine a multicausal analysis of undernutrition. The Food Frequency Questionnaire was tested for internal reliability among 30 adolescents. The reliability test for the actual dietary tool was done using Cronbach's alpha coefficient (α), which was 0.79. The model adequacy was tested using the Akaike information criterion and Bayesian information criterion. The significant direct and indirect determinants were identified with a value of p<
0.05. RESULT: Adolescents with lower traditional and mixed dietary pattern consumption habits were determinant factors for stunting with adjusted β=0.65, 95% CL (0.143 to 1.159) with a value of p=0.012, adjusted β=2.697, 95% CL (0.563 to 4.831) with a value of p=0.013, respectively. Breakfast eating frequency had a negative indirect determinant factor on the reduction of stunting via lower traditional habits, with adjusted β=-0.207 (-0.299 to-0.116) with a value of p=0.002, and higher consumption habits of animal sources with traditional alcoholic drinking habits with adjusted β=-0.163, 95% CL (-0.260 to -0.065) with a value of p=0.002. Whereas breakfast eating frequency had a direct influence on thinness with adjusted β=-0.332, 95% CL (-0.588 to -0.076) with a value of p=0.011, and an indirect influence via dietary patterns for both stunting and thinness (p<
0.05). CONCLUSION: Dietary patterns and breakfast-eating frequency were direct and indirect determinant factors for adolescents' stunting and thinness. Public health interventions should be implemented to reduce stunting and thinness by improving the dietary feeding and breakfast consumption habits of adolescents and strengthening the national deworming programmes in study areas and similar settings.