Methods for the detection of adulterated milk are essential for assessing the quality of goat milk products. We hypothesized that goat milk oligosaccharides could provide a basis for this purpose and compared the levels of α3'-galactosyllactose (α3'-GL) and N-acetylhexaminyllactose (NHL) between goat milk and bovine milk oligosaccharides using reverse-phase high-performance liquid chromatography. The α3'-GL was detected to be three times more abundant in goat milk than in bovine milk, whereas NHL showed the opposite trend. Linear relationships were established between the relative proportions of α3'-GL and NHL levels for different ratios of bovine and goat milk, with a minimum detection limit of 2% bovine milk. The new method was validated by analyses of adulterants in eight commercially available goat dairy products. Overall, the degree of adulteration in goat milk products can be determined based on the relative proportions of α3'-GL and NHL.