The present review highlights the synthetic methods of monoamine oxidase inhibitors (MAO) belonging to a group of nitrogen heterocycles such as pyrazoline, indole, xanthine, oxadiazole, benzimidazole, pyrrole, quinoxaline, thiazole and other related compounds (1990–2012). Moreover, it emphasizes salient findings related to chemical structures and the bioactivities of these heterocycles as MAO inhibitors. The aim of this review is to find out different methods for the synthesis of nitrogen containing heterocycles and their bioactivity related aspects as MAO inhibitors.