This study investigated relations between parent teaching, cumulative instability/chaos and school readiness in a group of 130 children attending a Head Start preschool. Cumulative instability/chaos negatively predicted fall school readiness as well as spring school readiness. Parent teaching did not predict fall school readiness but did predict spring school readiness. Fall school readiness predicted spring school readiness, suggesting the possibility that this variable helped to carry the effect of cumulative instability/chaos, as measured in the fall of the preschool year, to spring school readiness. Fall school readiness mediated the relationship between fall cumulative instability and spring school readiness. Implications for intervention efforts are discussed. (author abstract)