A simplified version of the prototype HIV vaccine material was developed through (a) reducing reading grade level, (b) restructuring of the organization and categorization of the material, (c) adding pictures designed to emphasize key concepts, and (d) obtaining feedback on the simplified version through focus groups with the target population. Low-income women at risk for HIV (N = 141) recruited from a primary care clinic were randomly assigned to be presented the standard or the simplified version. There were no significant differences between the groups in terms of education or Vocabulary, Block Design, and Passage Comprehension scores. Women who received the simplified version had significantly higher comprehension scores immediately following presentation of the material than did women who received the standard version and were also significantly more likely to recall study benefits and risks. These findings were maintained at 3-month follow-up. Implications for informed consent are discussed.