Chemical cleansing by denture cleansers is the first choice for denture plaque control of tissue conditioners. This study evaluated the influences of denture cleansers on the surface quality of tissue conditioners by determining surface roughness and porosity. Three tissue conditioners (Hydro-Cast, SR-Ivoseal, Visco-Gel) and 3 types of denture cleansers (Pika [enzyme type], Polident [neutral peroxide type with enzymes], Steradent [alkaline peroxide type]) were evaluated. Five specimens of each tissue conditioner/solution combination for each time period of immersion were prepared. The surface roughness of dental stone casts made from the tissue conditioners was evaluated using a profilometer. The surface quality of Hydro-Cast and Visco-Gel tended to be most deteriorated by the alkaline peroxide cleanser. The enzyme type of denture cleansers is most suitable for tissue conditioners in terms of surface quality. The suitable period for application of the enzyme cleansers would range from 3 to 7 days.