The zebrafish is a robust animal model for studying vertebrate haematopoiesis and immune cell interactions. However, fluorescence activated cell sorting (FACS) has been limited due to a paucity of available functional zebrafish antibodies. We have developed a technique combining FACS with whole mount in situ hybridization (WISH) that enables the sorting and examining of fixed zebrafish blood cell populations at different stages of embryonic development, providing the opportunity to correlate RNA expression data with cellular morphology.