The Upanisads represent a glorious religious-philosophical thinking that is at the core of the Indian tradition. An important Upanisad is the Ganapati Upanisad, found in the concluding part of the Atharvaveda, which deals with the worship of Isvara and reveals the nature of the ultimate Reality in which everything resolves. The book presents the text of the Ganapati Upanisad along with its transliteration in Roman script which is followed by a detailed commentary on its meaning that takes up each line for critical analysis. Beginning with a general discussion on the Upanisads, their associatioin with specific Vedas and their main purpose, Swami Tattvavidananda examines the nature of the Cosmic Power and the universe, propitiation of God, the purpose of living, concepts of ananta, ananda and others as explained in the Ganapati Upanisad. He explains the derivative roots of many words so that the concepts may be better understood by the readers. The commentary, in a language that demystifies esoteric concepts, includes many cross-references. The book will be extremely useful to scholars of Vedantic thought and Indian religious and philosophical traditions as well as general readers.