The neuroleptic malignant syndrome (NMS) has undergone a number of changes since it was first described in the 1960s. This paper presents a review of these changes from the traditional approach of rigid categorization through the more flexible operational definitions to a spectrum of neuroleptic toxicity. This spectrum spans neuroleptic-induced extrapyramidal side effects, possible stages of neuroleptic toxicity, and the full blown neuroleptic malignant syndrome. Different theoretical concepts of the syndrome have contributed to diagnostic confusion among clinicians and thus to difficulties in management. The concept of a spectrum of neuroleptic toxicity provides a coherent theoretical base for understanding NMS and thus allows for more rapid identification of the potential threat of NMS. Three cases are presented and discussed to highlight the utility of the concept of a clinical spectrum.