Objectives The existence of street and working children in Iran is undeniable. The precarious conditions of these children (including disrupted family, poverty, high prevalence of crime among relatives, family members and peers) cause social harm and high-risk behaviours, including drug addiction, selling sex or having sex with adolescents or peers. Here we explore the HIV, hepatitis B and hepatitis C status of street and working children in Tehran.

Methods One thousand street and labour children, aged 10–18 years, were recruited by using the time-location sampling method, and semistructured questionnaires were used to find demographic information and information on HIV/AIDS-related high-risk sexual behaviours. Blood samples were collected from children, with use of the dried blood sampling method.

Results 4.5% of children were HIV infected, 1.7% were infected with hepatitis B virus and 2.6% were infected with hepatitis C virus (HCV). Having parents who used drug, infected with HCV and having experience in trading sex significantly increased the likelihood of getting HIV among the street children of Tehran.

Conclusion HIV prevalence among street children is much higher than general population (<0.1%), and in fact ,the rate of positivity comes close to that among female sex workers in Iran. These findings must be an alarm for HIV policymakers to consider immediate and special interventions for this at-risk group.