ObjectiveThough gradual improvements are exist; Ethiopia’s learning outcomes are still low in primary schools. Academic achievement of school age children can be affected by several factors such as nutritional status, socio-economic and demographic factors. The aim of this study was to assess predictors of poor academic performance in Nekemte Primary school students, Western Ethiopia.ResultsA total of 362 schoolchildren and their parents were involved in the study. The study involved interviewing the participants and their parents, anthropometric measurement of participants and their document review. The prevalence of stunting and underweight was 30.2% and 45.9% respectively. Of the total study participants, 32.2% of them were poor in academic achievement. Variables like Being underweight (Adjusted odds ratio (AOR): 0.57; 95% Confidence interval (CI) 0.23–0.82), Skipping breakfast (AOR: 2.1; 95% CI 1.42–5.76), stunting (AOR: 0.66; 95% CI 0.12–0.93), being male (AOR: 2.8; 95% CI 1.79–4.52), participants whom mothers didn’t attend formal education (AOR: 0.62; 95% CI 0.37–0.92) were significantly associated with academic performance. Thus, Modifiable factors like under nutrition should be a great concern to improve the overall achievement of children in schooling.