This paper examines the degree of cartel formation in the Turkish banking industry for the period 2002-2011. Taking up a conjectural variation approach, it is found that Turkish banks appear to have exercised collusive pricing during the sample period. This result is a reflection of the fines imposed by the Competition Authority on March 8, 2013 after its recent investigation of the banking industry. It was also found that the size distribution of banking institutions is significant in explaining the differences in conduct patterns, and in particular, smaller banks have acted more collusively than larger ones. The estimation results also demonstrated that there has been less collusive behaviour among Turkish banks following the 2008 global financial crisis.