This paper examines the impact of interest rate reforms on financial deepening and economic growth in Kenya, using two models: the financial deepening model and the dynamic Granger causality model. The study attempts to answer two critical questions: Does interest rate liberalization in Kenya have any positive influence on financial deepening? Does the financial depth which results from interest rate liberalization lead to economic growth? Using cointegration and error-correction models, the study finds strong support for the positive impact of interest rate liberalization on financial deepening in Kenya - although the strength and clarity of its efficacy is sensitive to the level of the dependency ratio. The study also finds financial depth to Granger cause economic growth in Kenya. The study, therefore, concludes that the interest rate liberalization in Kenya has succeeded in increasing economic growth through its influence on financial depth. This applies irrespective of whether the models are estimated in a static long-run formulation (cointegration model) or in the dynamic formulation (error-correction model).