Problems in childhood and adolescence, such as pronounced externalising and internalising problems, are associated with a relatively high risk for long-lasting psychosocial difficulties. Therefore, it is essential to understand what protects youth from externalising and internalising problems. The present article has three purposes: (1) To review previous research reviews concerning which factors that have been identified as protecting youth from externalising and internalising problems, (2) to identify and suggest key areas of focus for future research, and (3) to discuss implications of this knowledge for practice. From the 29 included reviews, it can be concluded that an extensive list of factors have been identified as being potentially protective in youths. These factors exist in the individual and the family, as well as outside the family. However, from this review of reviews, it is also evident that many important questions remain unanswered. Answers to these questions would help make interventions for youths at risk more effective. How to use the existing research results concerning protective factors in guidance and counselling with youths is discussed.