Although a detailed description of the procedure and tissue used as controls is considered a necessary component in surgical pathology articles in which immunohistochemistry is utilized, such documentation seems less stringent in the cytopathologic literature. A comprehensive literature search was done for articles published in English within the last 15 years on nine of the most widely used antibodies in cytopathology. Individual case reports were excluded. Of the 100 articles reviewed, 13 articles were review articles or commentaries and hence not included in the analysis. Only 11 (13%) of the remaining 87 articles described positive and negative controls run on identically prepared samples. Forty-seven articles (54%) either did not mention controls or did not run controls as separate specimens. Sixteen articles (18%) included a vague statement about controls. Twelve (14%) commented only on the negative control, included only histology tissue controls, or included cell block controls, but the study also included other types of preparations, such as cytospins. One article (1%) did not include controls because of insufficient material. The College of American Pathologists recognizes the impracticality of maintaining separate positive control samples for every possible combination of fixation, processing, andspecimen type. However, more stringent documentation of procedure and use of controls in the cytopathologic literature will ensure that immunocytochemistry results in diagnostic cytopathology as well as in research are valid and reproducible. Diagn. Cytopathol. 2011;39:245–250. © 2010 Wiley-Liss, Inc.