The song is "the Emcee’s sardonic introduction" to the Kit Kat Klub, and is set within the cabaret itself.

Filmsite notes this "cheery greeting in German, French and English" contains "three languages to suit the club's cosmopolitan clientele [and] anticipates future hostilities between the three nationalities during wartime".

H2G2 writes The Emcee "Immediately evok[es] the decadent, cosmopolitan atmosphere of 1930s Berlin. 'In here, life is beautiful, the girls are beautiful, even the orchestra is beautiful... we have no troubles here.' These words of the Emcee will come back to haunt the characters later."

New Line Theatre wrote the following analysis on the song and its reprise:

The first song in Cabaret, "Willkommen", functions as both a comment song and a book song. It welcomes us both to the Kit Kat Klub where much of the action will take place, and also to Cabaret, the musical. The Emcee is addressing the audience in the Kit Kat Klub while he also addresses the real audience. Using the opening song this way prepares us for the two different uses to which songs will be put in the show. At the very end, the Emcee briefly reprises "Willkommen", perhaps an ironic welcome to the new Germany Ernst and the Nazis are building, but the Emcee doesn't finish the final phrase; the song stops, unfinished, and he disappears. We know the story is not over. Herr Schultz will undoubtedly be put in a concentration camp and murdered. And yet the Emcee is now happy to have helped us “forget” our troubles. Here at the end of the show, he says goodbye only in German (auf wiedersehen) and French (à bientôt). There is no English goodbye. The melody doesn’t end and neither does the lyric. The Emcee doesn’t finish his farewell.

USA Today described it as "deliciously bawdy". The Providence Journal described it as an "opening chorus". The Los Angeles Times said the song was "lascivious".