One achiral molecule of thioxanthone-anthracene (TX-A) is able to self-assemble into chiral nanowires by tuning the solvent with different polarity. Left- and right-handed nanowires with helix structure can be produced from chloroform and acetic ester solution of TX-A respectively. The SEM and TEM images confirm the formation of the helical nanowires. The results indicate that the solvent polarity has great influence in controlling of the self-assembly of organic molecules. The growth process demonstrates a promising pathway to investigate the self-assembling from achiral organic molecules to chiral aggregations. (C) 2008 Elsevier Inc. All rights reserved.