There is a lack of research examining secondary stalking and its effect on children who, in many cases, can be direct targets, or secondary survivors, of the stalking of their parent. The present study examines trauma reactions in children of stalking survivors in a Danish sample. It investigates the differences and similarities of such reactions across three age groups. Fifty-seven children were divided into groups depending on their age. The symptoms of the youngest group, 0–6-year-olds, were investigated by way of a maternal diagnostic interview. The two older groups, 7–11- and 12–19-year-olds completed the age-appropriate questionnaires, “Darryl” and “HTQ”, respectively, online. Twenty-two percent of the youngest group met the criteria for Post-Traumatic Stress Disorder (PTSD). Eighty-five percent of the middle age group and 58% of the older age group met PTSD diagnostic criteria. The findings illustrate that reactions to secondary stalking were predominantly within the arousal cluster of PTSD symptomology, with sleep disturbances and irritability commonly reported. The overall prevalence of children meeting PTSD diagnostic criteria in the sample was 56%. Future studies will benefit from larger samples and from knowledge of any pre-existing relationship between parent and stalker.