At its U.S. Premiere screening in the 1978 Los Angeles FILMEX, L.A. Times critic Kevin Thomas noted: “As demanding as it is awesome... a prodigious work of the imagination, expressing the unending misery and exploitation of Naples' wretched poor, as exemplified by a brother and sister whom we see born and matured in the postwar decades. Schroeter's style is as intensely operatic as ever, but here it becomes a way of illuminating profound social, political and moral concerns and of embracing a large and vivid spectrum of humanity. Truly unique, The Kingdom of Naples is impassioned, bemused, even at times hallucinatory. It's the kind of bravura, exhausting, yet exhilarating movie that film festivals are all about.” Ranging from 1946 to 1976, The Kingdom of Naples narrates its story in 16 sequences, with a commentary filling in missing years. Ron Holloway has noted that Schroeter is “influenced by neo-realism and the Rossellini-Germi-Olmi personal portraits of individuals and families....
“Schroeter's remarkable feel for atmosphere and docu realism stems from a long-term knowledge of the city and the people. He studied in Naples and has had a running acquaintance with events there over the past 15 years. Friends and acquaintances in Italy joined in the project, to such an extent that this could be called more an Italian film for Italians than a German one shot in Italy....”