The article reports investigations of the “topological” properties of benzenoid molecules which the author has performed in the last 20 years. Emphasis is given on recent developments and other scientists' contributions to these researches. Topics covered in recent books and reviews are avoided. The article outlines spectral properties, some aspects of the study of Kekule and Clar structures, the Wiener index as well as a number of graphs derived from benzenoid systems (inner dual, excised internal structure, Clar graph, Gutman tree, coral and its dual).