The aim of the study was to compare the use of roots and tubers’ starches (achira, melloco, cassava) and commercial starch, as additives for water based muds. The starches used, were extracted by washing, debarking, cutting, liquefying, decanting and grinding processes. The values for size, granule shape and granulometric distribution, water absorption index (WAI), water solubility index (WSI) and swelling power (SP), of natural and modified starches were studied. The modification was achieved by pregelatinization with 0.25% w/w calcium hydroxide. Muds were prepared in order to assess the influence of the origin, treatment and concentration of the starch on the viscosity, gel strength, yield point, loss of filtrate, before and after an aging. Modified starches before aging, as well as starches in the natural state and modified after aging, produce changes on the rheology of the system. The plastic viscosity, gel strength and yield point values, were comparable to those obtained with commercial starch. The origin and the concentration influenced the filtrate loss reduction. It was determined that the natural melloco starch at a concentration of 8 lb/bbl by its ovoid shape, average particle size, WAI, WSI and SP index higher than the rest of starches; allows the formation of low permeability cakes that reduce the loss of filtrate to a value of 6,75 mL/30 min, granting this specie an alternative potential use as a filtering controller.