This article explores historical constructions of Pap smear classification systems from 1917 to 1990. Using a social worlds/arenas analysis, we examine the perspectives and properties of all the major actors (both human and nonhuman) in the Pap smear arena, including implicated actors. Analytical emphasis is on interpretive struggles among different actors in this arena and centers on the consequences of such conflicts for global classificatory systems and on the global classificatory criteria. We describe some of the local clinical “work‐arounds” designed to resolve problems of classification standards in practice. In drawing theoretical conclusions, comparison is made between Pap smear classification systems and two other systems.