In this paper, I review the origins of Clinical Enzymology with special emphasis on the years between 1960 and 1980 when the greatest advances in the subject took place. These are described in relation to my own research interests and contributions, focusing upon subclinical hepatic damage caused by viral infection and by alcohol; myocardial infarction; detection of cervical carcinoma by vaginal fluid analysis; evaluation of pancreatic function; and the clinical implications of microsomal enzyme induction. Reasons are proposed for the failure of enzymology to attain the status of an autonomous medical specialty, in contrast to the success of similar fields of knowledge that grew up in the same era.