The Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signaling pathway is one of a limited number of signaling cascades that is extensively utilized for many developmental and homeostatic functions. The JAK/STAT pathway is evolutionarily conserved from insects to mammals, with homologous transduction machinery in each. Yet the mammalian pathway is composed of multiple members for each family of proteins, while flies have only a single homologue of most pathway components. This simplicity and the abundance of genetic, biochemical, and developmental tools make Drosophila an attractive model to investigate this important signaling pathway. This review provides a basic description of the Drosophila JAK/STAT cascade and summarizes currently available reagents and tools to study and manipulate the pathway.