To document the socioeconomic situation of street children in Iran and to ascertain the part played by this in becoming a street child, we classified and evaluated studies on this issue from the recent decade according to their strengths and weaknesses. The results will be helpful in policy-making and planning for this group. The study employed a systematic review methodology, searching Iranian and international databases, and many universities and related organisations in Iran. After the quality of studies had been evaluated by three researchers, the findings of 40 research studies were classified, described and analysed. The research finds that street children in Iran come from crowded, low-income families; many of them were rural–urban migrants and Afghans with families who immigrated to Iran; most of their parents had a lower than high school education and many of their fathers were unemployed or had low-income jobs; the majority of these children were unskilled workers who would work many hours of the day for negligible incomes. We conclude that low socioeconomic status was prevalent among the street children’s families in Iran and seems to be an important factor in the street-connectedness of the children.