The use of mindfulness-based interventions for different mental disorders has increased considerably in recent years. However, there is still little empirical evidence, as well as a strong controversy, concerning the efficacy of this modality of intervention in children and adolescents. In the specific case of anxiety, 20-50% of the children affected do not improve with traditional cognitive-behavioral therapy. Thus, this work aimed to present a systematic review on the effectiveness of Mindfulness-based interventions for the treatment of anxiety in children and adolescents. The search obtained a total of 15 articles, of which only seven fulfilled the inclusion criteria. All studies indicated that Mindfulness-based interventions provide positive results, such as a significant decrease in symptoms of anxiety and an improvement in the overall functioning. In short, it should be noted that Mindfulness-based interventions may be effective in children and adolescents with anxiety symptoms and/or disorders. However, it is still a developing field, comprising studies with multiple limitations, thus requiring further research.