This research presents a study on the influence of saturation procedures, used in commercial and research laboratories, on the stress-strain-strength behavior of residual soils when subjected to CIU triaxial tests. The selected soils are derived from different lithologies and show differences in mineralogical composition, structure and weathering degree. One of them belongs to the weathering profile of an alkaline rock located at the city of Tanguá-RJ. The others are the result of weathering processes on melanocratic and leucocratic features of a migmatite from Duque de Caxias, in Rio de Janeiro Metropolitan Area. Variation of the total volume of the test specimens was monitored during the saturation process in some tests to assess the influence of this procedure on the soil structure. For this purpose, it was developed a double-walled triaxial cell with a system based on the measurement of variation of the volume of the fluid filling the inner cell. The equipment has competitive technical features, besides the low cost and easy to assemble. The saturation technique based on percolating water by suction with a low cell pressure followed by continuous and simultaneous increase of backpressure (automatic saturation) was the most suitable method for the residual soil from the alkaline rock, which presents a weakly cemented structure, without bonding, and high voids ratio. However, the residual soil from the migmatite rock (melanocratic feature), which has strong cementation and high yielding stress, shown to be less susceptible to the saturation procedures, having its behavior affected only by the saturation technique of elevation of backpressure in just onestage.