The microscale topography of biomaterial surfaces has a great effect on the adhesion and proliferation behavior of cells. In this study, polylactide (PLA) films with regular micropitted surfaces were prepared by a phase-separation technique. The effect of the surface topography on the wettability and cell affinity was investigated with contact angle measurements and osteoblast incubation, respectively. The results showed that the shape of the pits could be controlled by changes in the film-forming parameters, including the PLA solution concentration, nonsolvent content, temperature, and solvent volatilization speed. These patterned films had significantly enhanced hydrophobicity because of the existence of micropits on the surface, and their hydrophobicity increased with the pit size increasing. Osteoblast spreading was improved on the patterned surface, and so was cell adhesion. However, the proliferation of cells on micropitted surfaces showed no distinction from the proliferation on smooth surfaces, and this indicated that the pit pattern had a great effect on the spreading and adhesion of cells but little on the proliferation of cells. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3162-3170, 2010