Autism spectrum disorders (ASD) are associated with a substantial economic burden, but there is little evidence of the costs in the early years; the period in which children are increasingly likely to be diagnosed. We describe the services used by 152 children aged 24-60 months with autism, report family out-of-pocket expenses and productivity losses, and explore the relationship between family characteristics and costs. Children received a wide range of hospital and community services including relatively high levels of contact with speech and language therapists and paediatricians. Total service costs varied greatly (mean 430 British Pounds per month; range 53 British Pounds to 1,116 British Pounds), with some families receiving little statutory support. Higher costs were associated with increasing age and symptom severity.