The risk that abortion may be correlated with subsequent mental disorders needs a careful assessment, in order to offer women full information when facing a difficult pregnancy. All research papers published between 1995 and 2011, were examined, to retrieve those assessing any correlation between abortion and subsequent mental problems. A total of 36 studies were retrieved, and six of them were excluded for methodological bias. Depression, anxiety disorders (e.g. post-traumatic stress disorder) and substance abuse disorders were the most studied outcome. Abortion versus childbirth: 13 studies showed a clear risk for at least one of the reported mental problems in the abortion group versus childbirth, five papers showed no difference, in particular if women do not consider their experience of fetal loss to be difficult, or if after a fetal reduction the desired fetus survives. Only one paper reported a worse mental outcome for childbearing. Abortion versus unplanned pregnancies ending with childbirth: four studies found a higher risk in the abortion groups and three, no difference. Abortion versus miscarriage: three studies showed a greater risk of mental disorders due to abortion, four found no difference and two found that short-term anxiety and depression were higher in the miscarriage group, while long-term anxiety and depression were present only in the abortion group. In conclusion, fetal loss seems to expose women to a higher risk for mental disorders than childbirth; some studies show that abortion can be considered a more relevant risk factor than miscarriage; more research is needed in this field.