This longitudinal study examined a multitude of early childhood predictors of anxiety symptoms and disorders over an 8-year period. The purpose of the study was to identify early life predictors of anxiety across childhood and early adolescence in a sample of at-risk children. The sample included 202 preschool children initially identified as behaviorally inhibited or uninhibited between the ages of 3 years 2 months and 4 years 5 months. Temperament and familial environment variables were assessed using observation and parent report at baseline. Anxiety symptoms and disorders were assessed using questionnaires and diagnostic interviews at baseline (age 4), and at age 6, 9 and 12 years. In line with our hypotheses, the findings showed that preschool children were more likely to experience anxiety symptoms and disorders over time i) when the child was inhibited, ii) when there was a history of maternal anxiety disorders or iii) when mothers displayed high levels of overinvolvement. Further, the study identified a significant interaction effect between temperament and maternal overvinvolvement such that behaviorally inhibited preschoolers had higher anxiety symptoms at age 12, only in the presence of maternal overinvolvement at age 4. The increased risk of anxiety in inhibited children was mitigated when mothers demonstrated low levels of overinvolvement at age 4. This study provides evidence of both additive and interactive effects of temperament and family environment on the development of anxiety and provides important information for the identification of families who will most likely benefit from targeted early intervention.