Mintzberg's (1990) critique of the ‘design school’ of strategic management is evaluated on two criteria: methodological soundness and factual veracity. The critique is found to be deficient on both criteria. Mintzberg's own proposal for the basic principles of strategic management is critiqued using the same criteria. It is found that the exposition is deficient methodologically and that Mintzberg's descriptive and prescriptive assertions are at variance with facts observable in the current practice of strategic management. The variance is found to be due to several factors: lack of coherence in Mintzberg's presentation; his use of a definition of strategy which is at variance with the current practice of management, his failure to differentiate between prescriptive and descriptive statements; and his failure to define the context for his prescriptions. Using recent empirical research results on strategic success behaviors, Mintzberg's model is placed in a limited but important context in which it is a valid prescription for successful strategic behavior.