From 2017 to 2019, he was the Senior Curator at the Perth Institute of Contemporary Arts – PICA, in Western Australia, and from 2009 to 2016, he held curatorial positions at MADRE, the Contemporary Art Museum of Naples, Italy. As a guest curator, he has also worked extensively.

Viola specialized in the experiences and theories related to performance. On this subject Viola most notably edited monographs devoted to Regina Jose Galindo (Skira, Milan, 2014); Hermann Nitsch (Edizioni Morra, Naples, 2013); Marina Abramović (Sole 24 Ore Cultura, Milan, 2012); and ORLAN (Charta, Milan- New York, 2007) among others,

and published many essays for international publications. He is a long-time contributor to North American Artforum. He is the Curator of the Italian Pavilion at the 59th Venice Biennale.