This paper reviews and critically evaluates the psychometric properties of Kolb's Learning Style Inventory (LSI). The LSI was developed originally in the 1970s (Kolb, 1976a) and was revised in the 1980s (Kolb, 1985). Although the LSI has been very popular, extensive evidence available in the published literature indicates that both the original and revised versions of the LSI are deficient in reliability and construct validity. It is concluded that the LSI does not provide adequate measures of learning styles and that its use in research should be discontinued. To improve understanding of the learning process, valid instruments are essential. An appendix presents three exhibits containing a learning style gird, a scoring key, and a list of investigations of the LSI. (Contains 86 references.) (Author/SLD)