Most leading causes of death, disease and disability in developing countries can be prevented, treated, or at least alleviated with cost effective essential medicines. Despite this fact, millions of people are deprived of access to essential medicines. Many of those who do have access, are given the wrong treatment, receive too little or too much medicine for their illness, or do not use the medicine correctly, adding to the problem of irrational use of medicines. Rational use of medicines is essential in today's situation, especially in a country like India, where there is a wide disparity in the availability of medicines amongst cities and villages. The concept of the rational use of medicines has not yet penetrated the minds of health care providers and the public, and as a result there is rampant irrationality in both the medicines available, as well as the medicines prescribed. This article, attempts to explain to all, the various aspects related to essential medicines, their rational use, their irrational use, the concept of Fixed Dose Combinations (FDCs), and the role of Education in the Rational Use of Medicines.