In recent years, microanalytical chemistry is making decisive contributions to the identification of psychoactive sources in archaeological contexts in different parts of the world. Most of the cases presented in this article were preceded and motivated by iconological studies which, directly or indirectly, were based on the reading of art, craftsmanship and graphic-symbolic aspects, and from which it was deduced the use of psychoactive sources. These iconological interpretations have often been considered as imaginative suppositions, but the concordance between form, decoration and chemical findings highlights how semantic language in archeology is not a secondary or negligible value. Archeometry is finally shedding light on controversial cases, and promises the birth of a specific discipline. The psychoactive sources taken into consideration concern the opium poppy, datura and ergot, traced in archaeological samples between California, the Eastern Mediterranean, Italy, Spain and Greece, and concern the art of the Chumash, the Daunians, Grotta dei Cervi in Porto Badisco, and other geographical areas.