Objectives: The primary objective of this pilot study was to examine the effectiveness of teaching first aid to 6–8-year-old children within their primary school setting. The study aimed to address two key research questions: (1) Can children of this age group acquire first aid and trauma management skills from their schoolteachers? (2) How long do children retain the acquired first aid knowledge? Methods: A pilot experimental study with an educational intervention was conducted in a single primary school in Greece. A total of 60 schoolchildren aged 6–8 years were randomly selected for participation, with 30 children assigned to the training group and 30 children assigned to the control group, which did not receive any intervention. To assess the children’s understanding of first aid, a specialized questionnaire was administered to all children one day before the training, as well as to the training group one day after the training, and at two and six months following the training. Results: Prior to the training, there were no significant differences in first aid knowledge between the children in the training group and those in the control group. However, one day after the training, the trained children demonstrated significantly higher scores (p< 0.05) compared to the control group. Over time, the first aid knowledge of the trained children gradually declined at the two- and six-month follow-up assessments, although it remained higher than their pre-training level. Conclusions: First aid training provided by their teachers improved the knowledge of 6–8-year-old primary school children in first aid and trauma management.