Compounding accounts for a relatively small section of the Polish lexicon of morphologically complex words, compared to a language like English. However, the process is fairly productive in Modern Polish. Moreover, there are specific types of compounds and areas of the vocabulary which, in recent years, have shown a remarkable spread or revitalization of this morphological process. This chapter focuses on the structural diversity and certain formal properties of Polish compounding that set it apart from compounding systems in many other languages, and discusses compound nouns and compound adjectives, interpreted as output categories.