The article explores the interactions between learners' age and achievement in rural and urban primary schools in a national education assessment in Ghana. The study sample comprised 12,207 learners from 349 public schools, and the data were analysed using multilevel modelling. The findings revealed a statistically significant and negative impact of age on mathematics and English language achievements. Rural and urban schools moderated the impact of age on academic achievement; however, they were unable to offset its statistical significance or the negative effect it exerted. The interaction between age and rural and urban schools detrimentally affected achievement in both subjects, especially in rural schools. The study findings suggest enrolling children in schools at the appropriate age and taking measures to eliminate the inequalities between rural and urban schools for a more equitable basic school curriculum implementation.