A discussion of the use of generative phonology in the speech clinic, especially with children, begins with an outline of some constructs of generative phonology. First, some notes on phonetic notation and definitions of terms used in nongenerative phonology that have special meanings in this field are presented. Then a discussion of distinctive features defines and distinguishes major class features, tongue body features, place of articulation features, manner of articulation features, and prosodic features and redundancy. The principles and writing of phonological rules in generative phonology are described, including rule conventions, phonological processes and rules, rule ordering, and rule collapse. Another section discusses the problem of relating abstraction to underlying forms as it occurs in clinical applications. Finally, a case study is used to illustrate the steps in applying generative phonology to the evaluation of a child's language. The steps include data collection, establishing the phonetic inventory and inventory of segments tested, making informal observations, writing formal rule statements, and making recommendations for therapy. (MSE)