BACKGROUND AND DESIGN: Analysis of the most frequently cited dermatology articles and the journals in which they appear identifies and emphasizes the impact of works of colleagues and predecessors, recognizes key advances in cutaneous medicine and surgery, and adds useful data about historical developments in dermatology. Use of citation analysis to examine the dermatologic literature reveals quantitative information about authors, articles, and journals helpful in identifying classic works and high-impact journals. We analyze the characteristics of all dermatology articles cited 100 or more times in one of the 10 most highly ranked clinical dermatology journals as indicated by the Institute of Scientific Information (Philadelphia, Pa) database from 1945 through 1990 and also discuss the standard and, as well, more recently described bibliometric indexes for dermatologic journals. RESULTS: Thirty-one institutions located in 11 different countries produced 129 landmark articles. Ninety-two percent of the citation classics originated in the United States, United Kingdom, Sweden, and Germany. There were 16 authors with three or more top-cited articles. Fifty-two percent of the articles were of the clinical type, 22% were clinical review articles, and 26% discussed basic science topics. The mean number of authors has increased gradually over the past 80 years. The average classic article was published in 1969, peaked in popularity 9 years later with 26 peer citations, and received only 11 citations in 1990. CONCLUSIONS: Citation frequency and citation analysis reveal useful and interesting information about scientific communication. The data on citation classics we describe can be interpreted in many ways, but certainly reflects the attention that articles have received over the past 48 years. The half-life of the average citation classic of about 10 years reflects the rapid pace of advances in the science and practice of dermatology over the past several decades. This information, along with current bibliometric indexes, may assist physicians in optimizing the time they spend reading the medical literature.