This study uses the Family and Child Experiences Survey (FACES) data from 1997 to investigate the degree to which child, family, classroom, teacher, and Head Start program characteristics are related to children's school readiness and continued development over the four-year-old Head Start year. Latent class analyses were used to examine the constellation of school readiness competencies within individual Head Start children in both the fall and spring of the four-year-old Head Start year. Multinomial regression analyses examined patterns of association between demographic and program characteristics and profile membership over time. Four distinct developmental profiles were found in the sample in the fall, and three were found in the spring. Furthermore, a substantial proportion of Head Start children (43%) moved from a developmental profile including some risk to a strengths profile between the fall and spring of the Head Start year. Child age, family structure, parental educational attainment, classroom quality and teacher's level of educational attainment emerged as important factors associated with stability and change in profile membership over the four-year-old Head Start year, but receipt of social services through Head Start was not associated with stability or change in profile membership. (Contains 6 tables and 2 figures.)