Currently marketed drugs are largely the products of accidental discoveries. During the period 1935-1965, systematic chemical modifications of known drugs and alkaloids lead to the synthesis of optomally bio-active derivatives. This period constituted the three golden decades of drug development. Presently it appears as if all available drug molecules have been fully exploited. The discovery of completely new compounds has become a necessity if major therapeutic advances are to be made. Empirical research including, re-examination of folk remedies, has become essential. The pathogenesis of certain conditions, e.g. hypertension, must be clarified before proper causal drug treatment can be instituted. Improved analytical methods applied during the last decade has tremendously advanced our insight into the pharmacokinetics of drugs. This has created an increasing gap between the clinician and the pharmaceutical industry. It is up to the pharmacologist to bridge this chasm. He has to teach the pharmacological basis of drug therapy so that the clinician can gain a better understanding of the principles governing the correct use of drugs in modern medicine.