摘要:Background. This study aimed to assess the prevalence of malnutrition and associated factors among school adolescents in Wolaita Sodo town, Southern Ethiopia. Methods. A school-based cross-sectional study was conducted from May 18–June 10, 2015. A multistage sampling was used to select a random sample of 690 adolescents from selected schools. Data on sociodemographic information were collected by using an interviewer-administered questionnaire, and anthropometric measurements were made by using a digital Seca scale and height measuring board by trained data collectors. Data were entered into Epi-Data version 3.1 software and exported to SPSS version 20. World Health Organization (WHO) Anthro-plus software was used to analyze anthropometric data. Both binary and multinomial logistic regression analyses were done to identify factors associated with the malnutrition of adolescents. Result. The overall prevalence of thinness, stunting, and overweight/obesity among school adolescents was 4.7% (95% CI: 3%–6.4%); 5.2% (95% CI: 3.4%–7%); and 5.0% (95% CI: 3.4%–6.7%), respectively. Being male (AOR = 4.07; 95% CI: 2.35–7.02), learning at a government school (AOR = 0.37; 95% CI: 0.20–0.65), mothers with no formal education (AOR = 4.03; 95% CI: 1.82–8.92), owning no cattle (AOR = 4.92; 95% CI: 2.08–11.64), skipping meals (AOR = 1.70; 95% CI: 1.05–2.74), and illness in 2 weeks prior to survey (AOR = 2.67; 95% CI: 1.49–4.78) were significantly associated with thinness. However, males, students who had their house, and no cattle were more likely to develop overweight/obesity. Maternal education of secondary school (AOR = 0.214; 95% CI: 0.054–0.846) was significantly associated with the stunting. Conclusion. The study showed the coexistence of undernutrition and overnutrition among school adolescents in the study area. There needs to implement evidence-based school nutrition education and health policies and programs to improve nutritional status of adolescents and timely taking action to limit obesity-related health problems.