Microfinance research concerns addressed in this thesis relate to: (1) targeting of clients vis-à-vis financial sustainability; (2) loan size effect of interest rate and clients’ well-being status; (3) economic governance and the dual objectives of microfinance institutions; and (4) patterns, trends and drivers of microfinance institution’s efficiency. The thesis emphasises operational issues that affect institutional performance and outreach of microfinance institutions rather than impact of microfinance intervention on poverty reduction. The thesis revolves around four empirical chapters that seek to address the above research concerns. Both micro and macro-level analyses have been explored with the aim of identifying institutional and public policies that drive the success of microfinance interventions. Micro level data from households in Ghana and cross country data mainly from the Microfinance Information Exchange (MIX) market are used. Varied microeconometric techniques (ordinary least squares, instrumental variable estimation, quantile regression, pooled regression, fixed and random effects estimations, Hausman-Taylor, Fixed Effects Vector Decomposition, stochastic frontier analysis and non-parametric efficiency estimations) are used depending on the hypotheses being considered in each of the empirical chapters. The main findings are: observed trade-off between financial sustainability and reaching poorer clients; formal institutions dispensing their own funds target poorer clients; pronounced variations in responsiveness of loan size to interest rate changes; semi-elasticity of loan amount responsiveness to a unit change in interest rate is more than proportionate and very significant for the poorest group; lesser time in securing property and availability of credit information show positive effects in targeting poorer clients; both type (pure technical and scale) and scope (narrow and broad) of financial efficiency show varying trends; and lastly, negative effects of bureaucracies in property registration and lack of credit information on social efficiency are also observed. This thesis suggests the following recommendations both for management of microfinance institutions and other stakeholders including international microfinance investors and government: harmonizing microfinance programmes irrespective of the source of funds; segmenting microfinance outreach markets based on socio-economic well-being; curtailing bureaucracies in property registration; and providing credit related information. These are paramount to the success of the microfinance paradigm, especially in achieving its social objective.