Cell adhesion plays a key role in various aspects of biological and medical sciences. In this study, poly(,N,-isopropylacrylamide) (PNIPAM) was grafted on polystyrene surfaces using different solvents under UV radiation. Moreover, the relation between surface roughness and cell adhesion were evaluated by gravimetric, SEM, AFM, contact angle measurement and cellular analyses. The gravimetric analysis clearly indicated an increase in the grafting by adding 10% methanol to water. The study of surface topography by AFM images showed an increase in the surface roughness and as a result of which, a decrease in wettablity was observed. At 37 ℃, epithelial cells were well attached and proliferated on the grafted surfaces, while these cells were spontaneously detached below 32 ℃ in the absence of any enzymes. Moreover, MTT assay and SEM images indicated good cell viability and an increase in cell adhesion caused by the roughness increase. The results of this study reveal the great potential of PNIPAM-grafted polystyrene for being used in the biomedical fields such as drug delivery systems, tissue engineering and cell separation.