BACKGROUND: Simplified informed consent forms have been successful in improving patient satisfaction and decreasing patient anxiety. However, unsolved problems remain about whether these documents improve comprehension and satisfaction of patients with standard literacy skills. PURPOSE: s To investigate whether a detailed consent form explaining the key elements of informed consent, in comparison to a standard consent form, would increase the comprehension and satisfaction of adult cancer patients. METHODS: Patients who were eligible for the National Surgical Adjuvant Study of Breast Cancer (protocol 01(N-SAS/BC-01)) were randomly selected to receive one of the following four versions: detailed document with graphics, detailed document without graphics, standard document with graphics, and standard document without graphics. The forms were written in plain language from the patients' point of view. A total of 85 patients were administered questionnaires via interview to assess levels of comprehension, satisfaction, and anxiety. RESULTS: Patients demonstrated a strong understanding of information regarding treatment and research. Patient comprehension did not differ significantly between the detailed document arms and the standard document arms. Patient satisfaction level increased according to the amount of information presented in the consent form; most patients preferred the detailed document with graphics. Anxiety and accrual rates in the parent study were not affected by informed consent procedures. LIMITATIONS: Findings were limited to adults who had standard literacy skills and may not be generalizable to a population with lower literacy. CONCLUSION: Informed consent can be a significant experience for a population with standard literacy skills, as long as the document is easily comprehensible. Such information should be provided in a format that corresponds with patient needs, education levels, and preferences.