Lip and palate cleft (cheilognathopalatoschisis) is most often congenital defect that affects craniofacial region. It is characterized by a difficult clinical presentation.The etiology is multicausal and not yet fully understood. The examination of numerous etiological factors imposed the need to study the role of stress in the development of lip and palate cleft. This is all the more important for the socioeconomic factors that characterized our society in the last years, after bombardment, poverty, higher divorce rate, and more family violence. The aim of this paper was to establish the importance of stressful events and their role in the development of lip and palate cleft. The examination included children born from March 1999 (time of war in this area), till December 2003, as well as their mothers.The study group comprised 96 children with the lip and palate cleft anomaly, and the control one included 142 healthy children. The chosen examinees were not under the influence of other etiological factors, such as heritage. The examination was conducted using a questionnaire containing questions related to stressful situations in the first trimester of pregnancy. The questions were thus formed so as to be clear to mothers of different levels of education, without expert phrases,except in the cases where it was necessary. The statistical differences between the study and control group were determined using Pearson's χ2 test. In the first trimester, the mothers of the study group, in regard to the control group,statistically more often had fears or anxiety (p<0.01), disorganized emotional life(p<0.001), more often phychological harassment (p<0.001), and the presence of any kind of harassment (p<0.001). The presence of stress was also greater in the study group, on the significance borderline in relation to the control group.The stressful situations to which mothers of the study group were exposed are in correlation with the increase of the children with lip and palate cleft.