There is a growing body of compelling empirical evidence for the efficacy of short- and long-term systematic compassion training. This chapter reviews the current scientific literature on the neurobiological correlates and putative consequences of these interventions. Despite the fact of much excellent work being done, research in this complex area of study is still very much in the nascent stage of development. There are many complex issues related to comparing findings across labs, across specific studies, as well as when comparing specific types of compassion training. Therefore, while we review and attempt to integrate the specific neurobiological findings from research with expert meditators practicing compassion in the context of Tibetan Buddhism, as well as findings from secularized and shorter-term training programs (e.g., Cognitively- Based Compassion Training (CBCT), Compassion Cultivation Training (CCT) and Project for Empathy and Compassion Education (PEACE), we also pay particular attention to some broader questions regarding how to interpret this research. Additionally, a series of brain maps provide graphical summaries of these complex neurobiological findings. We also offer some cautionary notes with respect to evaluating the empirical data with particular focus on the reliability and validity of extant fMRI analyses, assumptions regarding neuroplasticity, interpretations regarding causation, as well as important questions regarding possible gender differences that need to be considered. Directions for future research are also offered.