Industry 4.0 (I4.0) is a research field that accounted for an explosion of scientific publications since 2011. It is impractical to analyse the content of these many documents in a reasonable time (20,000). In these terms, the present research proposes a bibliometric review of this research field to identify its intellectual roots, research front, trends and gaps. The research settled for a must-read list, the past and current research themes and their evolution, and the supportive intellectual structure of the research field. It defined the research front under two general topics: "I4.0 implementation" and "I4.0 effects on sustainability," and it also presented thematic evolution trends and research gaps. Bibliometric analyses of the scientific field of I4.0 have several precedents: however, they have yet to embrace all the documents present in WOS and SCOPUS core collections. In this sense, the present article brings a novelty to the annals of the research field.