This paper aims to build an integrated account of the history of twentieth-century laboratories. The historical literature is fragmented, which has led to the impression that one type of laboratory has dominated, or has become more important than other types. The university laboratory has also unjustly shaped the conceptualization of other types of laboratory. This paper approaches laboratories as sites of organized knowledge production, and as entities engaged in different activities for different audiences at any point in time. Eight types (...) of laboratory are identified, and their developments in the twentieth century are sketched. The two world wars of that century and models of innovation, building links between knowledge production in the laboratory and the impact of this knowledge outside the laboratory, are important catalysts of this history. The paper underlines that different types of laboratory have existed side by side, and continue to exist side by side. (shrink)