Helitrons are a class of DNA transposons that employ rolling-circle intermediates for transposition, distinguishing themselves from other DNA transposons by leaving the original template element unaltered. They are characterized by unique terminal motifs and a strong preference for integrating at AT dinucleotide sites. Helitrons can capture and mobilize host genome fragments, leading to gene fragment duplications, genome rearrangements, exon shuffling, and the dissemination of regulatory elements. This review discusses the current understanding of Helitrons, including their origins, transposition mechanisms, and the extensive repercussions of their activity on genome structure and function. Helitrons have been shown to induce evolutionary conflicts through siRNA-mediated epigenetic silencing of captured genes. They also play a role in shaping genome structure, particularly in plants, where they contribute to genome diversity and the evolution of regulatory networks. The review highlights the challenges in identifying Helitrons due to their lack of terminal repeats and nonautonomous nature, and discusses the potential for using Helitrons as tools in genetic engineering and crop improvement.Helitrons are a class of DNA transposons that employ rolling-circle intermediates for transposition, distinguishing themselves from other DNA transposons by leaving the original template element unaltered. They are characterized by unique terminal motifs and a strong preference for integrating at AT dinucleotide sites. Helitrons can capture and mobilize host genome fragments, leading to gene fragment duplications, genome rearrangements, exon shuffling, and the dissemination of regulatory elements. This review discusses the current understanding of Helitrons, including their origins, transposition mechanisms, and the extensive repercussions of their activity on genome structure and function. Helitrons have been shown to induce evolutionary conflicts through siRNA-mediated epigenetic silencing of captured genes. They also play a role in shaping genome structure, particularly in plants, where they contribute to genome diversity and the evolution of regulatory networks. The review highlights the challenges in identifying Helitrons due to their lack of terminal repeats and nonautonomous nature, and discusses the potential for using Helitrons as tools in genetic engineering and crop improvement.