Oxytocin nasal spray led to social skill improvements in some children with autism, says an Australian study.

The social skills of children with autism improved after using a nasal spray containing the hormone oxytocin, according to a small Sydney study.

"The potential to use such simple treatments to enhance the longer-term benefits of other behavioural, educational and technology-based therapies is very exciting," said co-author Professor Ian Hickie.

The University of Sydney's Brain and Mind Centre study involved 31 children, aged three to eight, with autism receiving a twice daily dose of oxytocin for five weeks.

The treatment was found to significantly improve their social, emotional and behavioural issues.

About one in 68 children in Australia is diagnosed with autism, which affects social interaction and communication skills.

The most common side effects of the nasal spray were thirst, urination and constipation, the authors said in their paper published in Molecular Psychiatry.

They noted that behavioural therapies, which can improve social, emotional and behavioural issues, are time consuming, expensive and have mixed outcomes.

They believe their study is the first evidence of a medical treatment for the social impairments in children with autism.

"The next phase of this research is to understand exactly how oxytocin changes brain circuitry to improve social behaviour and document how related treatments might be used to boost learning of established social learning interventions," Prof Hickie said.