Many plant-based bioactive compounds have been serving as the origin of drugs since long ago and many of them have been proven to have medicinal value against various chronic diseases, including, cancer, arthritis, hepatic diseases, type-2 diabetes and cardiovascular diseases. However, their clinical applications have been limited due to their poor water solubility, stability, low bioavailability and extensive transformation due to the first-pass metabolism. The applications of nanocarriers have been proven to be able to improve the delivery of bioactive phytoconstituents, resulting in the enhancement of various pharmacokinetic properties and thereby increasing the therapeutic value of phytoconstituents. These biocompatible nanocarriers also exert low toxicity to healthy cells. This review focuses on the uses and applications of different types of nanocarriers to enhance the delivery of phytoconstituents for the treatment of various chronic diseases, along with comparisons related to bioavailability and therapeutic efficacy of nano phytoconstituents with native phytoconstituents.