With the advancement of the technologies in the pharmaceutical field, drug delivery systems have drawn an increasing interest over the last few years. Nowadays, the importance of pharmaceutical galenic research is turned towards Chronopharmaceutical drug delivery systems (CDDS) as they deliver the drug at the right site of action at the right time and in the right amount based on circadian rhythms, thus providing spatial and temporal delivery and increasing patient compliance. Sustained and controlled drug delivery system release the drug at a substantially steady rate of release per unit of time. However, there are instances where maintaining a constant blood level of a drug is not desirable. In such cases a pulsatile drug delivery may be more advantageous. A pulse has to be designed in such a way that a complete and rapid drug release is achieved after the lag time. The aim of this current review is to describe, the diseases requiring CDDS, methodologies involved for the existing systems and more focus on the time induced and stimuli induced methodologies, recent update and CDDS product currently available in the market. Keywords: Pulsatile, lag time, circadian rhythm, time induced, stimuli induced