This study aims to evaluate the psychosocial factors of neonaticide, especially the circumstances before delivery, the relationships of the pregnant women, and their social environment awareness of women's pregnancy. This nationwide study was register-based, comprising all known neonaticides in Austria and Finland between 1995 and 2005. Cases (n = 28) were obtained by screening the death certificates from coroner's departments and by analyzing them along with all further available reports. Few women (17.9 %, 5/28) admitted their pregnancy to others. Although most (16/28) offenders were in a relationship, the partner had knowledge of the pregnancy in only three cases. The main motive for negation of the pregnancy (named in 60.8 % of cases) was fear of abandonment/negative response from others. The fertility rate among the women was high, but half of those with children had lost the custody of them. In neonaticide, the lack of awareness surrounding offenders' pregnancy, as well as the awareness of social environment, is more relevant than any other social variable.