The phenylalkylamine, particularly the phenylethylamine, moiety is a common structural feature found embedded in many clinically approved agents. Greater still is its occurrence in drugs of abuse. The simplest phenylethylamine, 2-phenylethylamine itself, is without significant central action when administered at moderate doses, but fairly simple structural modifications profoundly impact its pharmacology and result in large numbers of useful pharmacological tools, agents with therapeutic potential, and in drugs of abuse (e.g., hallucinogens, central stimulants, empathogens), the latter of which are the primary focus here. In vivo drug discrimination techniques and in vitro receptor/transporter methods have been applied to understand the actions of these phenylalkylamines and their mechanisms of action. Thus far, depending upon pendent substituents, certain receptors (e.g., serotonin receptors) and monoamine transporters (i.e., serotonin, dopamine, and norepinephrine transporters) have been implicated as playing major roles in the actions of these abused agents in a complex and, at times, interwoven manner.