Children with traumatic brain injuries (TBI) commonly present with socioemotional difficulties, as well as accompanying multiple cognitive impairments. Often difficulties worsen at around 10 years old. This change is associated with frontal system changes, and tests of executive function (EF) predict outcome. However, children with TBI sometimes present with socioemotional difficulties despite apparent cognitive recovery. Our aims were to explore potential cognitive and socioemotional effects following childhood TBI, before and after the age of 10 years. We also wanted to identify cognitive correlates of psychosocial dysfunction. Measures of cognitive function and socioemotional disturbance administered to 14 children with TBI aged 8-10 years, and 14 children with TBI aged 10-16 years, were compared to control data from 22 non-injured 8- to 10 year-olds and 67 non-injured 10- to 16-year-olds. Results indicated that only the older group of children with TBI were impaired in tests of EF, but significant socioemotional difficulties were commonly evident in both groups. Processing speed (as well as EF) was found to correlate with socioemotional disturbance. We conclude that poor processing speed may also index the risk of socioemotional difficulties, but our general findings indicate that cognitive functions relevant to socioemotional functioning are not readily testable in younger children and are not strongly associated with such outcomes as they may be in adults.