Seven-year-old children with reading disabilities (RD-only), behaviour problems (BP-only), both conditions (RD-BP) and neither condition (Comparison) were compared on indices including temperament and behaviour, gathered in five periods between infancy and 6 years of age. The RD-BP group differed clearly from the RD-only group from infancy onwards. This comorbid group was similar to the BP-only group, while the RD-only group was similar to the Comparison group, until school age. The gender composition of the two RD groups differed, and the RD-BP boys showed the most problematic characteristics. The findings indicate different developmental pathways for "pure' RD children and those with comorbid BPs.