We report a facile method for large-scale exfoliation of bulk molybdenum disulfide (MoS2) and tungsten disulfide (WS2) in the presence of sodium cholate through ball milling. The exfoliated sample can be stored as a "stock solid" and is readily dispersed in water just by shaking by hand, giving a highly concentrated dispersion (up to 4.2 and 2.6 mgmL(-1)) of MoS2 and WS2 nanosheets with up to 93% and 57% yields, respectively, after centrifugation.