RNA transcripts serve as pivotal components of cellular function, engaging in dynamic interactions with various proteins and other RNA molecules to modulate a myriad of biological processes. A comprehensive grasp of RNA biosynthesis and processing, coupled with their functional roles within cells, is indispensable for deciphering the intricate mechanisms of cellular operation and the pathogenesis of diseases linked to RNA abnormalities. This chapter is dedicated to exploring advanced live RNA imaging techniques, providing an in-depth analysis of the principles that govern these methodologies, while critically assessing their strengths and identifying potential limitations. This chapter extends to a detailed examination of a diverse spectrum of applications that underscore the versatility of RNA imaging techniques across different biological organisms and cellular contexts. This approach not only illustrates the adaptability of RNA imaging tools but also enhances our understanding of cellular dynamics and regulatory mechanisms at the molecular level. Moreover, this chapter delves into the significant role of RNA imaging technologies in investigating the progression of diseases associated with mutant RNA transcripts, particularly those characterized by triplet repeat expansions. By delineating how these mutant RNAs contribute to disease pathology, RNA imaging emerges as a powerful tool, offering profound insights into the molecular foundations of genetic disorders. This exploration illuminates the potential of RNA imaging to transform our understanding of complex disease mechanisms, thereby advancing diagnostic approaches and refining therapeutic strategies. Through this comprehensive review, this chapter aims to highlight the transformative impact of RNA imaging in the field of molecular biology, demonstrating its critical role in advancing our understanding of health and disease.