For the past three years MDPI has announced the newly released impact factors for its Open Access journals by the means of an annual editorial [1-3]. In 2012 we are-once again-pleased to report that the growth of the impact factors of MDPI's Open Access journals continues. This year's edition of the Journal Citation Reports (JCR), which is published annually by Thomson Reuters, includes 10 journals published by MDPI, including three that have received their first official Impact Factors- International Journal of Environmental Research and Public Health (IJERPH), Materials Nutrients. Table 1 reports the latest Impact Factors for 2011. Figure 1 graphically depicts the evolution of the Impact Factors for four MDPI open access journals that have received Impact Factors in the past. Table 2 reports the ranking of the MDPI journals within the subject categories of the Science Citation Index Expanded.