One of the most important aspects of monetary policy is an understanding of the transmission process: the mechanism through which the monetary policy actions of the Central Bank impact on aggregate demand and prices by influencing the investment and consumption decisions of households and firms. Thus, commercial banks are regarded as conveyers of monetary policy shocks and are expected to adjust retail interest rates in response to policy shocks one-to-one. In practice, commercial banks adjust their retail rates in response to changes in monetary policy with a lag of several months and this delay is often viewed as an impediment on the ability of the Central Bank to steer the economy. Several reasons, such as credit rationing and adverse selection, switching costs, risk sharing, consumer irrationality, structure of the financial system, menu costs and asymmetric information are some of the causes advanced for commercial banks retail rates being sticky. In spite of the important role of pass-through analysis in the monetary policy transmission process, it has received very little attention in Sub-Saharan Africa, especially in Cameroon and Nigeria, which have implemented a series of reforms. To this end, this study gives a comparative analysis of interest rate pass-through in Nigeria and Cameroon using retail rates (lending and deposit) and a discount rate (policy rate) from January 1990 to December 2010 for Nigeria and from January 1990 to June 2008 for Cameroon. The study examines the magnitude and speed of retail rate adjustments to changes in the Central Bank policy rate as well as examining the possibility of symmetric and asymmetric pass-through in both countries. In addition, the study also investigates whether there is pass-through of monetary policy from one country to the other. The empirical analysis employs four different types of co-integration techniques to test the presence of a long run co-integrating relationship between retail and the policy rates in order to ensure that the relationship detected is robust. Three sets of analyses are carried out in the study. Following Cottarelli and Kourelis (1994), the study employed a co-integration technique, firstly, to analyse pass-through for the entire sample, secondly, to analyse symmetric and asymmetric pass-through using a ten year rolling window analysis in an error correction framework. Finally, the policy rates were swapped around to investigate if there are transmissions of impulses from one country to the other. Overall, evidence from the entire sample and rolling window analysis suggests that monetary policy in Cameroon is less effective. This is perhaps one of the reasons why the Banque Des Etats De L’Afrique Centrale (BEAC) is unable to sterilise the excess liquidity of the banking sector in Cameroon. The long run pass-through of 0.72 and 0.71 for the entire sample, and the average long run pass-through for the rolling window of 0.78 and 0.76 for the lending and deposit rates, suggest that monetary policy is highly effective in Nigeria compared to Cameroon. The empirical evidence confirmed asymmetric adjustment in six rolling windows in the lending rate in Nigeria. Three rolling windows indicated that the direction of rigidity is downward, supporting Scholnick’s (1996) collusive pricing arrangement between banks, and the other three suggested that the lending rate is rigid in the upward direction, corroborating Scholnick’s (1996) customer reaction hypothesis. The deposit rate in Cameroon was also found to adjust asymmetrically and the direction of rigidity is downward, supporting Hannan and Berger’s (1991) customer reaction hypothesis. The investigation of impulse transmission between the two countries revealed that only the policy rate in Nigeria exerts some influence on the deposit rate in Cameroon. Policy recommendations are also discussed.