The establishment of the United Nations after World War II raised hopes of a new era of peace. This was over-optimistic. Between 1945 and 1992, there were 149 major wars, killing more than 23 million people. Recent developments in warfare have significantly heightened the dangers for children. During the last decade child war victims have included: 2 million killed; 4-5 million disabled; 12 million left homeless; more than 1 million orphaned or separated from their parents; some 10 million psychologically traumatized. Researches indicate that children do develop PTSD after experiencing very stressful, life-threatening events such as happen in war. Wars of 21st century are often guerrilla-type civil wars in which women and children are not only the main victims, but are deliberately targeted. Thousands are displaced both internally and across borders. Wars at the end of nineties of 20th century in the region of ex Yugoslavian countries brought all the cruelty of war vivid again on European ground. Population were exposed to death, threatened death, actual or threatened serious injury, or actual or threatened sexual violence. During the War in Bosnia and Herzegovina 1992-1995 there were about 100 000 people killed (20% woman and 3.5% children) and about 18 000 children were orphaned because of war. Children are not capable to regulate their emotions and hyper-arousal on their own. It depends of the way how their parents (caretaker) regulate her/his own emotions. During the war weak child's ego is paralyzed with intensive stimuli and floating anxiety, it does not manage to make constructive solution for traumatic experiences in such a short time. Mothers with small children are especially vulnerable group during the war time: they are supposed to take care about children and feel happiness, what is almost impossible Severe war experiences could cause depressive symptoms in mothers, what reduce their emotional disposability and could lead in different form of the child's neglecting. PTSD symptoms were lasting longer in children if their mothers have had functioning problems. Traumatization of mothers is connected with different behavior problems in their children. Wars are continuing all over the world and there is a continuity of researches about their consequences on children. Any programs that intend to mitigate the psychological effects of such trauma need to adopt a public health approach aimed at reaching many thousands.