Recent developments have led to a lot of emphasis being placed on early childhood education. Massive growth has also occurred in this segment of the education sector. Emphasis continues to be placed not just on growth but also on quality of the educational experiences that children are exposed to. In Kenya reports continue to emerge of pupils in primary school who lack numeracy and literacy competencies expected at their level. This inevitably shines the spotlight on the quality of educational experiences at the preschool level, which lays the foundation for all future learning and later success in school. One of the parameters of quality is parental involvement. In Kenya this parameter happens to be amongst the least understood. This paper sought to shed some light on the contribution of this aspect of quality to primary school readiness in preschool pupils in Nairobi. Parental involvement at six levels of involvement was measured for a sample of 150 parents of preschool pupils, while primary school readiness was assessed for a sample of 156 pupils. The results indicate that four of the six levels of parental involvement have a positive correlation to primary school readiness, while two are negatively correlated. The researcher recommends that schools and educators explore ways of creating and enhancing parental involvement so as to tap into the associated and recognized benefits of such cooperation.