The development of the financial sector is one of the main macroeconomic goals for developing countries as well as developed ones. The literature focusing on the determinants of financial sector development presents very diverse and inconsistent results. Therefore, the main aim of the study is to empirically investigate the long run and causal linkages between natural resources, economic growth, savings, current account balance and financial sector development for 33 developing countries. The study applies the cross-sectionally augmented autoregressive distributed lag (CS-ARDL) and Dumitrescu-Hurlin panel causality tests, which are among the new panel data techniques. The results reveal that natural resources, economic growth, savings, current account balance and financial sector development are cointegrated. Natural resources, economic growth and current account balance negatively affect financial development while savings stimulate financial development. It is found that there exists a bi-directional causality between all the explanatory variables and financial development. Theoretical and policy implications are discussed within the perspective of macroeconomics and financial sustainability for developing countries.