THIS INVESTIGATION was undertaken to determine the distribution pattern and readability level of 20 widely distributed printed items containing periodontal health education literature. Average annual distribution was obtained from distributors of the material. The Minnesota Interactive Readability Approximation Program (MNIRAP) was used to determine the reading skill (educational grade level) necessary to understand each of the pieces of literature. Results indicated that over two million pieces of printed materials were distributed annually. The MNIRAP analysis revealed that three of the 20 materials studied (15%) would be understood by persons reading at sixth-grade level. Those reading at the 10th-grade level would understand seven of the 20 materials (35%), while the 12th-grade level would allow individuals to understand 17 of them (85%). Only those reading as well as a typical third-year college student could be expected to understand all of the materials analyzed.