This study examined deposit insurance schemes’ activities and its effect on deposit mobilization of the International Association of Deposit Insurers (IADI) member countries. The study dwelled on the banking sectors post-core principles of the member countries. The study assessed the effect of deposit insurance fund, deposit insurance cover, deposit insurance premium and deposit fully covered on the total deposit of the banking sectors of 21 member countries of IADI spanning the period 2014 to 2018. Data were sourced from the annual reports of the selected countries Deposit Insurance Agencies. The study adopted the ex-post facto research design. The estimating technique was panel Vector Error Correction Model (VECM). Findings from the analyses showed that deposit insurance scheme activities of member countries did not significantly affect IADI’s member countries banking sectors deposit mobilization after the implementation of the core principle. IADI, as a policy-making body must, therefore, review and localize its core principles and policies in line with member countries’ uniqueness and financial realities through investment in research in member countries to isolate unique factors peculiar to member countries and streamline policies to capture member countries’ financial and economic conditions. IADI should monitor the compliance level of member countries to ensure strict implementation of its policy and principles by member countries.