From 2000 to 2006, Wahler ran the SI (Swiss Institute – Contemporary Art) in New York and curated large projects with artists such as Christoph Büchel, Jim Shaw, Ugo Rondinone, Valentin Carron, Urs Fischer, Takashi Murakami, Martin Creed, and Aleksandra Mir.
Exhibitions include solo- and group exhibitions with artists such as Diane Arbus, Louise Bourgeois, Bruce Conner, William Eggleston, Howard Hodgkin, Robert Irwin, André Kertész, Paul McCarthy, Catherine Opie, David Reed, Ugo Rondinone, Ed Ruscha, Lucas Samaras, Kazuo Shiraga, Shōmei Tōmatsu, Franz West, Terry Winters, Lucas Blalock and Constantin Brâncusi.
Ugo Rondinone | Ugo Foscolo | Ugo Mifsud Bonnici | Ugo Rossi | Ugo Mulas | Ugo Tognazzi | Ugo Pasquale Mifsud | Ugo Mattei | Ugo Fano | Ugo Savarese | Ugo Poletti | Ugo Monye | Ugo Intini | Ugo Falena | Ugo Ehiogu | Ugo Cavallero | Ugo Betti | Ugo Balzani | UGO | Pier Ugo Calzolari | Iginio Ugo Tarchetti |
Artists from 21 countries participated with fifty-eight sculptures from various artists like Anthony Caro, Jean Tinguely, Anthony Gormley, Marcel Pinas, Salvador Dalí, Ryas Komu, Lu Shengzhong, Eko Prawoto, Thomas Houseago, Jaume Plensa, Atelier van Lieshout, Subodh Gupta, Yayoi Kusama, Jean Dubuffet, Rodin, Dennis Oppenheim, Ugo Rondinone, Joost Conijn etc.