Potassium channels are important modulators of cell function depending on the cell type of where they are expressed. They are involved in regulation of cell membrane resting potential, potassium homeostasis and control a variety of cellular functions including metabolism. In this study we determined that a regulator of Pigment dispersing factor, PDF-immunoreactive neurons in the Drosophila melanogaster adult brain, is an inwardly rectifying potassium channel, IRK1. Knocking down the potassium channels specifically on PDF expressing neurons using UAS-GAL4 RNAi system resulted in altered axonal projections of lateral neurons (LNv) towards the dorsal neurons (DN). Moreover, it was observed that lack of the potassium channels also caused a robust increase in sleep and reduction in the fly’s active period during the day. We observed that the normal circadian control of the morning and evening anticipation is also dependant on these potassium channels. The flies deficient in IRK1 channels didn’t show an evening anticipation peak. Another interesting disclosure during this study was the inability of PDF-Tri neurons to undergo programmed cell death in the absence of inwardly rectifying potassium channels. Hence, IRK1, though poorly expressed in the Drosophila central nervous system, plays an important role in the normal functioning of PDF expressing neurons. Further studies are needed to elaborate the physiological roles of Drosophila potassium channels which may lead to a better understanding of human Kir channels related to pathological conditions and diseases.