This chapter describes dopamine (DA) and drugs used for Parkinson’s disease. Dopamine first synthesized in 1910. DA consists of a catechol moiety linked to ethylamine. It is closely related to melatonin. Dopamine is neither excitatory nor inhibitory it’s rather modulator; influenced by both excitatory glutamate nor inhibitory GABA input. Drugs of abuse cause increase in DA in nucleus accumbens. DA receptor agonists are now used in treatment of Parkinson’s disease, restless leg syndrome and hyperprolactinemia, major limitation being lack of receptor selectivity. This chapter covers the physiologic actions, drugs used in Parkinsonism, and drug-induced Parkinsonism.