The study examines the influence of the repo rate on the interbank rate and analyses whether the transmission channels of interest rates have changed since the adjustment to the repo system in September 2001. The paper employs the Granger causality test using the ECM framework. The results suggest that the influence of the repo rate on the interbank rate was stronger before the adjustments to the system were made. The interbank rate and the repo rate were found to "reverse" roles in the period after the adjustments to the system. Our results show that the changes to the repo system in 2001 did not lead to the achievement of the intended transmission channel; instead it was found that the system in place before the changes were made was in fact already achieving the transmission path that the authorities hoped to accomplish by changing the system. Copyright 2005 Economic Society of South Africa.