Background: Iran (Persia) has a women-only drug treatment system. However, literature is not documented. The current study aimed to review the development of women-only drug treatment and harm reduction services (WODTHRS) and the factors associated with treatment entry and outcomes in Iran. The review was based on a comprehensive search for all literature focusing on WODTHRS in Iran. Methods: Data were collected by conducting systematic searching of scientific English and Persian databases and grey literature. This was done in line with Cochrane Guideline for conducting systematic reviews. Overall, 19,929 studies were found. But, only 19 original studies were included after excluding non-relevant studies. Results: The review findings indicate how WODTHRS have been developed in the past 15 years. The review findings underscore the roles of numerous factors in treatment entry such as the side effects of illicit drug use. In addition, cognitive-behavioral interventions, methadone treatment and some factors outside drug treatment such as family support increase positive treatment outcomes among women. Conclusions: The review results highlight that eliminating barriers to treatment entry and positive treatment outcomes should be addressed. Conducting randomized controlled trials is needed to evaluate the effectiveness of WODTHRS. This issue should address the factors influencing service utilization to incorporate the best practice for women. The evaluation of the long-term efficacy of WODTHRS is a critical research gap which should be addressed in future studies.