Annual worldwide losses to weeds are estimated to comprise approximately 10-15% of attainable production among principal food sources. Worldwide consumption of herbicides represents 47.5% of the 2 million tons of pesticide consumed each year. However, the heavy use of herbicides has given rise to serious environmental and public health problems. It is therefore important to develop new herbicide formulations that are highly effective, that are safer (for the worker and for the environment), and that involve a low cost/production ratio. In this sense, controlled release formulations of herbicides have become necessary in recent years, since they often increase herbicide effi cacy at reduced doses. The present work reviews in detail the components of various types of herbicide formulations, with an emphasis on controlled release formulations and micro-encapsulation.