The following reflection paper aims to review the theoretical postulates of the New Economic Institutionalism (NIE), from its foundations to the relevant issues. It clarifies its main characteristics and disagreements with respect to the Original Classical Institutionalism (Veblen-Ayres tradition). It focuses on the historicity of the Coase/Williamson theoretical enterprise, the importance of the institutional logos and the description of its basic unit: transaction costs. It welcomes literature from its primary exponents and more rigorous researchers associated with the NIE agenda. It raises some issues that could oxygenate the NIE agenda, opening spaces for stimulating academic debate in the future research section.