A superhydrophobic material was synthesized using a one-pot approach via the self-hydrolysis and condensation of polymethylhydrosiloxane (PMHS) under a base catalyst in ethanol and water media. The obtained superhydrophobic polymethylhydroxysiloxane (PMHOS) material was stable up to temperatures as high as 500 °C, even under strong acidic and basic pH conditions. The micro–nano particles of PMHOS exhibited a hierarchical morphology with a mesoporous structure. The superhydrophobic PMHOS, however, become superhydrophilic by calcination at 600 °C. The superhydrophobic and superhydrophilic PMHOS exhibited a good ability to adsorb organic dyes at a certain pH (pH 12).