This review discusses the recent advancements in smart micro/nanoparticles (MNPs) for stimulus-responsive drug and gene delivery systems. MNPs are designed to respond to various stimuli such as pH, redox potential, temperature, magnetic fields, light, and ultrasound, making them versatile tools for targeted drug delivery. The review highlights the unique properties of these MNPs, including their ability to be tailored for specific therapeutic applications, their potential to reduce side effects, and their enhanced efficacy compared to traditional drug delivery methods. The mechanisms of action for different types of MNPs, such as thermo-responsive, magnetic-responsive, electrical-responsive, and light-responsive particles, are detailed. Additionally, the review covers the challenges and future prospects in the field, emphasizing the importance of understanding the underlying mechanisms to further advance nanomedicine.This review discusses the recent advancements in smart micro/nanoparticles (MNPs) for stimulus-responsive drug and gene delivery systems. MNPs are designed to respond to various stimuli such as pH, redox potential, temperature, magnetic fields, light, and ultrasound, making them versatile tools for targeted drug delivery. The review highlights the unique properties of these MNPs, including their ability to be tailored for specific therapeutic applications, their potential to reduce side effects, and their enhanced efficacy compared to traditional drug delivery methods. The mechanisms of action for different types of MNPs, such as thermo-responsive, magnetic-responsive, electrical-responsive, and light-responsive particles, are detailed. Additionally, the review covers the challenges and future prospects in the field, emphasizing the importance of understanding the underlying mechanisms to further advance nanomedicine.