The need for marketing in financial institutions cannot be over emphasized because it is a vital arm of any sector. Competition within and outside the shores of the country brought about by globalization and an improvement in customer awareness have made banks to use marketing as an important tool to increase returns, improve on the efficiency of the Nigerian banking system and compete efficiently. This study set out to investigate the impact of marketing of financial services in the Nigerian banking industry with specific focus on deposit money banks. The method used in testing the hypotheses is the T-test method. One hundred and twenty (120) questionnaires were distributed to selected deposit banks and One hundred and one (101) was retrieved. The hypotheses tested found that marketing of bankís products and services has improved the efficiency of deposit money banks banking system and created satisfied bank customer. We recommend that all the units of the bank should be involved in marketing while banks should continue to make their customers feel important and have well equipped and experienced staff personnel in customer services unit to be able to provide solutions to customerís complaints and challenges.