Within a longitudinal study using a large representative, community sample of infants recruited at mean age 8 months, we examined influences on infant communication development at 24 months, including child gender, shy temperament, behavioural and emotional problems, and several variables relating to maternal psychosocial health. On most developmental measures girls were in advance of boys and they also showed shyer temperament. Child gender, shy temperament and maternal psychosocial indices were associated with both vocabulary development as measured by the MacArthur-Bates Communicative Development Inventory (CDI), and communication and symbolic development assessed via the Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS) at 24 months. No prediction was found using scores at 8 or 12 months, although moderate stability between measures between 12 and 24 months was evident. Predictors of 24 month outcomes were all concurrently measured variables, and included temperamental shyness, but very little variance in communication outcomes was explained. Children whose mothers were experiencing clinical levels of depression and life difficulties reported more child behavioural problems.