In continuation of the Covance Primate Symposium Series, the 19th Covance Primate Symposium took place in Münster on 23rd & 24th of May 2012. Altogether, 70 participants representing 43 organisations, gathered for this symposium.The 2012 Primate Symposium focussed on >Challenges in Nonhuman Primate Research in the 21st Century<. The broad participation and the lively discussions during the symposium underlined the timeliness and importance of this topic. Expert speakers covered four major topics, i.e. biosimilars development: regulatory implications, key considerations and next steps, optimizing nonhuman primate use in nonclinical safety assessment, trends in nonhuman primate developmental & reproductive toxicology (DART) and juvenile toxicity evaluation, and relevance and importance of nonhuman primate models in regulatory toxicology. The development of biosimilar has taken up speed considerably and meanwhile needs to be considered a significant factor of potential drug development, yet there are still some uncertainties und guidelines are under development. With the increased focus on biopharmaceuticals and the associated increase for using nonhuman primates being the relevant animal model, it became necessary to optimize the use of this animal model, e.g. refine study designs and animals numbers but still execute meaningful preclinical studies. It appears that significant progress has been achieved in that context. In the area of nonhuman primate DART and juvenile toxicity evaluation, recent guideline changes had a major impact on species selection, and the experimental design plus the timing of these studies within the preclinical programmes. Finally, given the increasing regulations and justficiations of using nonhuman primates as experimental models. It is paramount to understand the essential and indispensable role that nonhuman primates can play in drug safety evaluation and medical drug development.