This study examined the dynamic relationships between child, parenting, and family-related predictor variables and early childhood externalising behaviour problems. A community sample of 395 Australian children was followed longitudinally, and assessed at 4 and 6 years with the Child Behavior Checklist, Teacher Report Form, and standard measures of parenting, temperament, and familial adversity. Variables based on the average scores across the two assessments and the change in scores between assessments were utilised as predictors of parent-reported and teacher-reported externalising behaviour problems at age 6. It was hypothesised that both higher average scores and more detrimental changes in scores, would independently predict externalising problems at age 6. Multivariable analyses found that the presence of parent-reported child externalising problems in six-year-olds were predicted by: (i) the presence of parent-reported child externalising problems at age 4, (ii) higher average "teacher-reported child externalising behaviour," "inflexible temperament," "non-persistent temperament," and "over-reactive parenting," and (iii) an increased "inflexible temperament" score between age 4 and age 6. The presence of teacher-reported child externalising problems at age 6 was predicted by higher average "parent-reported child externalising behaviour," and "over-reactive parenting." The results provide further evidence of the adverse impact of continuing high levels of temperament difficulties and over-reactive parenting on externalising behaviour in early childhood. However, contrary to expectations, the contribution of including the dynamic change scores was limited.