A study of undergraduate medical students' abilities to identify salient information in reviewing patient charts was conducted by members of the Department of Surgery at Southern Illinois University School of Medicine. Specific goals of the two-year study were to develop and test a method for assessing chart skills and to test the following hypotheses: (a) knowledge base is a component of chart review skill; (b) chart skills are related to basic observational skills; (c) performance on one chart is positively correlated with performance on other charts; (d) chart performance is affected by distraction and time pressure; and (e) chart performance improves with clinical experience. Evaluation instruments and methodology are described. Hypotheses a, b, and e and the time effect hypothesized in d were supported; hypothesis c was not supported. Results of the study provide a foundation for further research exploring the effect of instruction on chart performance and investigating the relationships between chart performance and other measures of clinical competence.