BACKGROUND: As a result of HIV-related mortalities more than 13 million children under the age of 15 have lost a parent due to HIV and AIDS. There are also many children who have HIV-positive parents or primary caregivers; these children are affected by HIV and AIDS and are potentially vulnerable to HIV transmission. Children affected by HIV and AIDS are more vulnerable and face greater challenges to their psychosocial well-being compared to other children of the same age. Interventions have been adopted with the aim of improving the psychosocial well-being of children affected by HIV and AIDS. OBJECTIVES: The primary objective of this review was to assess the effectiveness of interventions that aim to improve the psychosocial well-being of children directly affected by HIV and AIDS. SEARCH STRATEGY: Electronic databases were systematically searched using pre-defined search terms. Internet searches of relevant organizations involved in HIV and AIDS work were conducted and experts in the field and were contacted directly. Searches were conducted between January and September 2008. SELECTION CRITERIA: Randomised controlled trials, crossover trials, cluster-randomised trials and factorial trials were eligible for inclusion. If no controlled trials were found, data from well-designed non-randomised intervention studies (such as before and after studies), cohort, and case-control observational studies were considered for inclusion. Studies which included male and female children under the age of 18 years of age, either orphaned due to AIDS (one or more parents died of HIV related-illness or AIDS), or vulnerable children (one or more parents living with HIV or AIDS) were eligible for review.Interventions that aim to improve the psychosocial well-being of children affected by HIV and AIDS were included in the review. This included psychological therapy, psychosocial support and/or care, medical interventions and social interventions. Psychosocial outcomes were defined as any intervention that measures psychological and/or social factors. DATA COLLECTION AND ANALYSIS: Two of the authors independently screened the results of the search. The full text of all potentially relevant studies were obtained and were independently assessed by the two reviewers using pre-determined criteria. MAIN RESULTS: No studies of interventions for improving the psychosocial well-being of children affected by HIV and AIDS were identified. AUTHORS' CONCLUSIONS: Current practice is based on anecdotal knowledge, descriptive studies and situational analyses. Such studies do not provide a strong evidence base for the effectiveness of these interventions. IMPLICATIONS FOR RESEARCH: This systematic review has identified the need for high quality intervention studies. In order to increase the quality and quantity of such studies there is a need for greater partnerships between program implementers and researchers. IMPLICATIONS FOR PRACTICE: In the absence of rigorous intervention studies, the body of knowledge available consists of "lessons learned," child psychological theory and other related research in the adult population. However, such knowledge should not replace the urgent need for rigorous monitoring and evaluation of existing programs and intervention studies to ensure evidence-based practice and policy, and prevent subjecting children to interventions which show no benefit or interventions that could unintentionally lead to harm.