Responding to environmental threats and securing nourishment are the most fundamental actions an animal needs to perform to ensure survival. In the past few decades, a lot of emphasis has been given to the basal forebrain (BF) cholinergic influence in threat-related cue processing and food intake, however very little is known about the functional role of other more abundant neural populations in the BF. Here, I sought to determine how BF GABAergic neurons contribute to defensive threat responses and feeding behaviors. First, I examined if BF GABAergic neurons are necessary for fear memory retrieval, then I assessed when this neuronal population is recruited. Using optogenetic tools, I discovered that BF GABAergic neurons support cue-evoked freezing and that activity of these neurons during fear conditioning is necessary to influence freezing at later timepoints. Furthermore, I demonstrated that activity of this neuronal population modulates cue-elicit freezing during early extinction training, but do not enhance extinction memory retrieval. While several studies demonstrate that BF GABAergic neurons send long-range projections to the medial prefrontal cortex (mPFC), a key structure for fear expression, how BF GABAergic inputs in mPFC might affect fear memory retrieval remains unexplored. In this study, I provided evidence that fear expression modulation is mediated through BF GABAergic afferents in mPFC. Lastly, I evaluated how the activation of BF GABAergic neurons influence feeding drive. I uncovered that photostimulation of BF GABAergic neurons results in consumption of food as well as non-edible items in well-fed mice. In addition, stimulation of these cells disrupts defensive threat responses and elicits reward-like motivational effects. Finally, BF GABAergic activity triggers skilled predatory attack of live prey and prey-like objects. Interestingly, these effects were entirely recapitulated by selective stimulation of BF GABAergic projections to the periaqueductal gray (PAG). Taken together, our findings demonstrate that BF GABAergic neurons are involved in regulating fear expression and inhibition, feeding drive and reward.