Gamma-aminobutyric acid (GABA) ergic neurons are important for controlling sleep and wakefulness but are difficult to identify, limiting their study. Knock-in mice with GABAergic neurons labeled by expression of green fluorescent protein (GFP) under control of the glutamate decarboxylase 67 (GAD67) promoter are now extensively used in neuroscience. However, it is unknown whether these mice have a normal sleep phenotype. Compared with wild-type control mice, GAD67-GFP knock-in mice had the same amount of non-rapid eye movement (NREM) sleep and rapid-eye movement (REM) sleep, a similar diurnal distribution of sleep, no NREM or REM sleep differences in electroencephalogram power, and normal sleep rebound following 6-h sleep deprivation. Our results suggest GAD67-GFP knock-in mice are an excellent tool for study of GABAergic neurons involved in sleep-wake regulation.