Background For decades, child labor has been an important global issue associated with inadequate educational opportunities, poverty and gender inequality. In order to make effective policies to reduce child labor it is important to understand the specific factors that affect it. We aimed to investigate the main factors affecting child labor n Iran. Materials and Methods There are authoritative websites on the topic of working children in Iran, including the WHO, UNFPA, UNDP, Web of Science, ProQuest, Medline, Scopus, and CINAHL databases for reviewing studies conducted in Iran. Articles from internal dissertations and Google's databases, SID, Magiran, and Iran Doc during the period 1985 to June 2019 were included. Quality of studies was reviewed by the STROBE checklist. Information was extracted by two blind researchers. Results A total of 9 studies were identified (including 17, 219 on child labor), the majority of which were cross-sectional. Affecting factors on child labor and Street children were grouped into four categories such as "Family problems", "Urbanization", "Social and Cultural", and "Personality". Conclusion In the contemporary Iranian society, many children, for some reasons including personal, family, social and cultural, and urbanization problems, are involved with important social damages such a child labor. These factors make children vulnerable and endanger the health of the community.