The 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. (Contains 1 table and 2 footnotes.)