Twenty-seven young (X- = 27.3 years) and twenty-seven old (X- = 67.7 years) female volunteers participated in a study of the effect of vocabulary level upon memory and comprehension of prose materials. Comprehension was measured by presenting five multiple choice questions simultaneously with half of the prose passages. Memory was measured with the rest of the materials by presenting questions only after a passage was completed and removed from sight. The results indicated that age-related differences varied inversely with vocabulary levels but did not interact with type of task. No significant differences were found between age groups at the highest vocabulary level. The parallel findings for the two tasks suggest that inadequate comprehension represents one major factor underlying age-related differences in the retention of meaningful materials. A second memory task, not dependent upon accuracy of comprehension, indicated age-related differences at all vocabulary levels. This suggests that old adults may also hve deficits in the ability to maintain in store and/or retrieve meaningful materials.