Hydrophobically modified hydroxyethyl celluloses (HMHEC) are derivatives of water-soluble hydroxyethyl-ethers of cellulose. Because these amphiphilic molecules are known to adsorb strongly on water–oil interfaces, they were tested as nonionic surfactants and stabilizers in emulsion polymerization. Styrene and methyl acrylate were used as water-insoluble and slightly water-soluble monomers, respectively. In situ nucleation, seed latex polymerization, and postpolymerization addition of HMHEC were examined. The main difficulty with the HMHEC materials is their bridging effect, which enhances aggregation. However, these nonionic materials impart pronounced stability to latices against electrolytes. This property can be achieved also by postaddition of the HMHEC to a performed emulsion.