Anime News Network offers this in its review: "Great story, great direction, great visuals, great anime!" and has this plot summary:
Tracking the legendary counterfeits known as "Goat Bills," international thief Arsene Lupin III arrives at the Duchy of Cagliostro. Once there, he nearly rescues a damsel in distress from the Regent's guards. Following his failure, Lupin takes it upon himself to save her from captivity.Anime World calls it "a wonderful, action-packed adventure with enough substance and characterization to appeal to both the young and the young at heart." DVD Talk says, "If you haven't seen The Castle of Cagliostro before, then what are you waiting for? There is no longer any excuse. Unless you don't like having fun, in which case I don't know what to tell you." Rotten Tomatoes gives it a 90% critics rating.