The CNAE-74 constitutes an initial step in the process of harmonising the systems of nomenclatures and classifications within the realm of economic classifications. The publication is organised into four parts. The first part includes the presentation and the introduction. The second part summarises the historical and conceptual framework in which economic classifications are developed for statistical purposes, and specifically a presentation of the characteristics of the CNAE-74. The third part contains the 1974 Classification of Economic Activities (CNAE-74), explanatory notes for the content of the most disaggregated categories, a brief version of the classification up to two digits and a subject index aimed at making inquiries easier. The fourth part includes the annexes where the terminological criteria and bibliographic materials used are set out.