AbstractThe advantages of emphasizing discrete trials teaching over discrete trials training are presented first, followed by a discussion of discrete trials as a method of teaching that emerged historically—and as a matter of necessity for difficult learners such as those with autism—from discrete trials as a method for laboratory research. The elements of discrete trials teaching are presented next, and after that a set of guidelines for discrete trials teaching is given and elaborated upon. A final note on deciding what to teach and how best to teach it concludes the article. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 667–679, 2007.