Daisy Miller starts out in a hotel in Vevey, Switzerland when a gentleman named Winterbourne meets Daisy, a young, beautiful American girl traveling through Europe. Daisy, her younger brother Randolph and her mother, Mrs. Miller, are traveling all over Europe while her father is home in Schenectady, New York. While Daisy is in Europe, she does not accept European ideas to be her own. Winterbourne, to the contrary, has been living in Europe since he left America when he was younger. Winterbourne takes a strong liking to Daisy even though his aunt, Mrs. Costello, does not approve of him even speaking to Daisy. Winterbourne claims that Daisy is an innocent person, but his aunt believes she is too common and not refined enough for him. Winterbourne and Daisy spend much time together, and even had a date at a close by castle named Chillon. Winterbourne then returns to Geneva where he is studying, but agrees to visit Daisy again that winter in Rome.
When winter comes around Winterbourne goes to Rome to visit Daisy. While Winterbourne was away Daisy met a suitor named Mr. Giovanelli. Later, when a mutual friend named Mrs. Walker throws a party, Daisy arrives with Giovanelli. Mrs. Walker does not approve of Daisy being seen in public with all of these men and makes the decision to stop speaking to Daisy. Daisy is not happy about Mrs. Walker snubbing her, but still continues to be with Giovanelli. Daisy continues to be with Giovanelli even while Winterbourne is visiting. Winterbourne inquires as to whether or not Daisy is engaged to Giovanelli which she doesn’t answer right away. One night, Winterbourne decides to stop by the colosseum on his way home from a party and he encounters Daisy and Giovanelli. He advises them to leave and he too becomes fed up with Daisy’s behavior. Shortly after, Daisy becomes ill with Roman Fever.
When Winterbourne goes to visit Daisy in the hotel, Mrs. Miller gives him a message from Daisy saying she is not engaged and she asks him to remember the trip they took to the castle Chillon in Switzerland. Winterbourne realizes that Daisy was indeed innocent and that she was just looking for companionship. Soon After, Daisy dies of Roman Fever. Winterbourne feels guilty for the way he treated Daisy, and he decides he has spent too much time living abroad.
Daisy’s attitudes were frowned upon by the European culture and European Americans, such as Winterbourne. Differences in the social etiquettes of Americans and Europeans were obvious when Daisy and Winterbourne interacted. When Winterbourne first met Daisy, she talked very freely as if she had known Winterbourne for quite sometime. In Europe it was not customary for men and women to talk so openly in public, especially since they did not know each other. Throughout the story, the differences between the American and European cultures are shown through the journeys of the independent minded Daisy Miller in a European society that was refined and full of customs that the American did not want any part of.