Early childhood education (ECE) programmes are increasingly recognised as crucial for cognitive development in children, particularly in low- and middle-income countries where access to quality ECE is limited. The study employs a longitudinal qualitative research design, utilising in-depth interviews and observations conducted in rural and urban settings across Tanzania. Participant selection was informed by socio-economic status and geographic distribution. Children who participated in ECE programmes demonstrated significant improvements in cognitive skills, including memory recall and problem-solving abilities, with a proportion of 75% showing notable enhancement compared to their peers without such interventions. The findings suggest that early childhood education can have lasting positive impacts on cognitive development, particularly when implemented in diverse socio-economic contexts. Future research should explore these effects across more regions and over longer periods. Policy makers are encouraged to prioritise the expansion of ECE programmes, especially focusing on areas with higher needs, to ensure equitable access to quality education for all children.