Gene-based therapy plays a crucial role in precision medicine through gene inhibition, addition, replacement, or editing. This approach has achieved remarkable success in the treatment of many diseases such as neuromuscular diseases, liver metabolic diseases, and ocular diseases. The multi-omics integration significantly advances our understanding of the molecular mechanisms underlying tumorigenesis and tumor development, revealing a plethora of potential oncological targets. In this chapter, we aim to provide a comprehensive analysis of the progress made in small RNAs (including antisense oligonucleotides, short interfering RNAs, microRNAs, aptamers, etc.) for cancer therapy and highlight their potential as effective therapeutic agents by elucidating their roles in regulating gene expression and modulating key pathways involved in tumorigenesis. Furthermore, we delve into the chemical modification strategies utilized in clinical and preclinical studies. This review encompasses the significant advancements and remaining challenges in small RNA research. It emphasizes the promising potential of small RNAs to revolutionize cancer treatment strategies, ultimately leading to improved patient outcomes.