Objective(s): Unsafe abortion is the main problem of women during their reproductive age. This study was carried out to explore the reasons behynd illegal abortion in Iran.Methods: This was a qualitative study. Twenty-seven participants were interviewed during March and September 2006 about illegal abortion process. All participants had an experience about illegal abortion or their occupation was relevant to the one aspect of illegal abortion. Interviews were analyzed using a content analysis method.Results: Five main themes emerged from analysis: motivations for ending unwanted pregnancy (social factors, familial factors, personal factors), the assessment of situation (reactions, religiousand individual beliefs, socio-politics restrictions), definite decision, changing the mind, doing abortion by the help of fassilators (the role of partner, previous experiment, doing abortion in general or private centers, doing abortion by herself) and abortion outcomes (physical outcome social outcome, mental outcome, juridical outcome).Conclusion: Illegal abortions are usually performed by unskilled practionnaires. Since, in Iran abortion is illegal, finding ways to protect women against malpractice needs urgent attention.