Qualitative investigation can provide invaluable information towards understanding the influence of school nutrition education (NE). The study explored teachers' perceptions of the immediate impact of NE on learners' eating behaviours. Twenty-four primary school teachers in the Bronkhorstspruit district, Gauteng, South Africa, who taught nutrition topics to grades four to seven learners, participated in three focus group discussions. Transcript data obtained was analysed using the thematic approach of the framework method. Findings indicated that school support for NE was limited, which undermined the capacity of school NE to influence healthy eating behaviours of learners. The need to strengthen teachers' capacity to model positive eating behaviours was identified. Learners were perceived as being not completely ignorant of healthy eating, with limited capacity to effect changes within the resource-constrained environment. Negative influences like unhealthy choices of food from food vendors and peer influences were identified as needing to be discouraged. Positive influences like the National School Nutrition Programme (NSNP) and the school vegetable garden were to be encouraged. Understanding the prevailing school situation and environment and teachers' perceptions and roles in school NE is important in addressing issues that weaken the influence of NE on learners' eating behaviours.