The main purpose of this note is to give a self-contained proof of Puig’s structure theorem for nilpotent blocks. Puig’s original proof appeared in [8]. Textbook accounts were given by Ku¨lshammer in [6] and by The´venaz in [9]. The present proof makes use of simplifications discovered by Ku¨lshammer, Okuyama, and Watanabe [7]. The exposition is based upon lectures given by the author in Budapest in 2000.