Loihi Seamount is an active submarine volcano located 30 km southeast of the Island of Hawaii and considered to be the youngest shield volcano to be formed by the hotspot of the Hawaii-Emperor volcanic chain. Sixteen samples from Loihi were analyzed for Pb, Sr, and Nd isotope ratios using a Nu plasma multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS) and a thermal ionization mass spectrometer (TIMS) at San Diego State University. Fresh glass pieces were chosen by handpicking under a binocular microscope. Previously, isotopic variations of Hawaiian lavas have been attributed to two explanations: (1) mixing of at least three discrete end member sources within the Hawaiian plume and/or (2) lithosphere contamination of plume-derived magmas. Samples were analyzed for Pb, Sr, and Nd isotope ratios in order to better characterize the source of Loihi lavas, and to compare Loihi with other Hawaiian volcanoes. One source must contain high 206Pb/204Pb and 208Pb/204Pb, a second source consisting of low 206Pb/204Pb and 208Pb/204Pb and a third source that has low 143Nd/144Nd and 87Sr/86Sr at a given 206Pb/204Pb. These isotopic variations cannot be explained by assimilation of the mantle lithosphere or melting of the ambient asthenosphere. Instead, variations in isotope values and rock compositions at Loihi are explained by the tapping of different small-scale heterogeneities within the Hawaiian mantle plume. Three distinct sources are then required to create the isotopic variability seen in Loihi lavas. Loihi demonstrates that there is sampling of small-scale mantle source heterogeneities also seen in other Hawaiian volcanoes.