Patient education is an integral component of the care most hospital patients receive. The use of printed health material is widespread due to its perceived benefit and convenience. Unfortunately, there is a discrepancy between reading level of many materials selected for patients and the reading ability of the intended reader group. Although research suggests the need for simplified text, ease of reading is only one component of readability; the other is comprehension. This article presents results from a study completed in 1990 and replicated in two hospitals the following year. Using a Cloze technique, researchers tested patient's ability to understand health information prepared at grade levels five and nine. Scores revealed that 77% of subjects were able to comprehend material prepared at the grade five level independently, 8% required some assistance, and 14% were not able to comprehend the material. When comprehension of the material prepared at the grade nine level was tested only 30% of subjects were able to comprehend it, 31% required some help, and 39% were unable to comprehend it. These results suggest the importance of simplifying health material to no higher than a grade five level so it is comprehensive to the majority of hospital patients.