The screening of novel compounds to predict potential toxicity to the hematopoietic system (i.e., hematotoxicity) is an important step in drug development. This webinar discusses the importance of hematotoxicity testing in drug development, reviews methods for in vitro assay standardization, and explores the use of both colony-forming unit (CFU) assays and lineage-specific liquid culture-based assays as tools for in vitro drug screening.