This paper describes the effect of pre-migration and post-migration experiences on the mental health of a sample of 40 refugee children aged 8-16 who lived in London with at least one parent or a refugee relative. Children's post-traumatic stress disorder (PTSD) and depression symptoms were assessed with standardised self-report measures (Impact of Event Scale and Depression Self-Rating Scale for Children, respectively). Information regarding past and present experiences were gathered during an interview with parents. There was a significant correlation between the number of pre-migration traumas experienced by the families and the children's PTSD scores. There was also a significant correlation between the families' number of post-migration stresses and children's depression scores. Higher PTSD scores were significantly associated with the pre-migration experience of violent death of family members and the post-migration experience of an insecure asylum status. Higher depression scores were significantly associated with insecure asylum status and severe financial difficulties. The clinical implications of these findings are discussed.