Originally reported in 1964, the Psychiatric Case History Event System has been implemented on a large scale in a study of the decision‐making process in psychiatric diagnosis. The Event System is a generalized information‐processing system for conversion of case history data into computer acceptable form for subsequent retrieval and analysis. The details of the processing of data from point of transcription to computer output are now presented. In so doing, the logic of the system, and its generality for application in a variety of clinical and research endeavors, are made evident.