Scale-up potential of cultivating Chlorella zofingiensis in piggery wastewater for simultaneous wastewater treatment and biodiesel production was tested. The cultivation of C zofingiensis with autoclaved wastewater and NaClO-pretreated wastewater, cultivation of algae indoors and outdoors, and stability of semi-continuous feeding operation were examined. The results showed that C zofingiensis cultivated in piggery wastewater pretreated by autoclaving and NaClO had no evident difference in the performance of nutrient removal, algal growth and biodiesel production. The outdoor cultivation experiments indicated that C zofingiensis was able to adapt and grow well outdoors. The semi-continuous feeding operation by replacing 50% of algae culture with fresh wastewater every 1.5 days could provide a stable net biomass productivity of 1.314 g L-1 day(-1). These findings in this study can prove that it is greatly possible to amplify the cultivation of C zofingiensis in piggery wastewater for nutrient removal and biodiesel production. (C) 2013 Elsevier Ltd. All rights reserved.