Phototaxis is a basic response to environmental stimuli in the fruit fly Drosophila melanogaster.Drosophila larvae, which prefer darkness to light, receive visual input from 2 bilateral groups of 12 photoreceptor neurons, known as the Bolwigs Organ (BO), which deliver output directly to pdf-expressing neurons in the central brain.Blocking both the BO and pdf neurons causes blindness in larvae, suggesting that these neurons underlie the visual information flow that guides larval phototaxis.We examined the neurons involved in larval phototactic behavior, and found that inhibiting the function of 2 pairs of larval CNS neurons that are putatively post-synaptic to pdf neurons results in a preference for light, as opposed to the preference for darkness observed in wild type larvae.Our results extend knowledge of the neural circuit that mediates larval phototactic behavior, and also elucidate the neural circuit that controls larval preference between light and darkness.