In just over 25 years, the zebrafish has emerged as a valuable model to discover genes controlling vertebrate development, owing to its amenability to mutagenesis and unbiased phenotype-based screens. The transparency of early developmental stages enables abnormal morphology to be readily detected in many organs and tissues types, including the central nervous system. The same attribute makes embryonic and larval zebrafish well suited to cataloging spatial patterns of gene expression and for time-lapse imaging of fluorescently labeled cells. The application of mobile transposable elements expedites the production of transgenic animals, thereby advancing techniques to visualize neuronal populations and their axonal projections, to selectively destroy them, or to manipulate their synaptic activity. Neural activity of specific regions or throughout the brain of a live, behaving larva can be monitored by transgenic strategies capitalizing on genetically encoded calcium indicators. This chapter will outline how such genetic and transgenic approaches are being applied to study left-right (L-R) asymmetry of the zebrafish brain, to learn how and where it develops, and examine its impact on neural processing and lateralized behaviors.