Walter Keiniger is a partner at Marval, O’Farrell Mairal. He obtained his law degree at the University of Buenos Aires, School of Law (1994), with a specialisation in Tax Law. He also holds a Master of Laws in Taxation from the University of Florida, USA (2003), a degree earned at the Graduate Tax Program of the University of Buenos Aires, School of Economics (1997) and attended a course of specialisation in Tax Law at the University of Salamanca, Spain in 1998.

He has been recognised as one of the main tax lawyers in Argentina by prestigious publications such as Chambers and Partners, Legal 500, World Tax and Latin Lawyer 250. He has also been recognised as a leading tax attorney in Argentina and thought leader 2018 and 2019 by LACCA (Latin American Corporate Counsel Association) and has been awarded back-to-back the 2018 and 2019 Client Choice Award for Corporate Tax in Argentina.

He is a member of the Argentine Fiscal Association, the International Fiscal Association, Transnational Taxation Network (TTN) and STEP. He was visitor professor of the University of Florida (USA), the University of Miami (USA) and is an invited professor at UADE (Universidad Argentina de la Empresa). He was joint director of the transfer pricing unit (2016) and since 2017 is joint director of the international taxation unit of the Argentine Fiscal Association.