The comprehension of numerical concepts that appear in written health educational materials is an important aspect of health literacy. Health materials that include many advanced numerical concepts may place high demands on readers, especially those with low health literacy levels. The purpose of this study was to examine and document the types of numerical concepts that appear in passages selected from written diabetes educational materials that varied in their type of content. Readability of the passages was also analyzed. One hundred and fifty passages of 100 words each were selected from 50 diabetes-related educational documents, produced by major health organizations. Passages were coded for type of numerical concept, SMOG Reading Grade Level, Flesch Reading Ease, and features that elaborated the numerical concepts, such as pictures or explanations. Findings indicate that passages containing general information about diabetes and its prevention contained significantly more advanced numerical concepts, the highest reading grade level, the lowest reading ease scores, and the lowest frequency of elaborative features, relative to many other types of content. Recommendations are made for enhancing the presentation of numerical concepts in written diabetes educational materials.