In one scene just outside the Perlman's house, it is possible to see three cans of Illy coffee; in 1983, the design of the cans was different: shorter and larger. On top of that, the Illy logo displayed on the cans on display was created by James Rosenquist only in 1996.
As soon as Oliver's train has left the station of Clusone, Elio calls his mother on the phone, asking her to come and pick him up. The train station of Clusone was a bus only station by 1983, as the railway line of Valle Seriana (in the province of Bergamo) closed down in 1967 to be substituted by a bus line.
The book that Elio gave to Marzia is the collection of poems "Parole" [Words] by Antonia Pozzi, curated by Alessandra Cenni and Onorina Dino and published for the first time by Garzanti in its series Poesia in 1989 (while the movie is set in 1983).
When professor Perlman shows Oliver Greek slides we can see a sleeve of a coffee table book facing camera which reads "Palaces Of Florence". The first edition of this book was published in 1995, so 12 years after the film's story line.
The Persol sunglasses Oliver wears throughout would have had a 4-barrel "Meflecto" temple in 1983; only after Luxottica bought the company in the 2000s did they reduce the 649 to 2 barrels, which is seen in the film.
When Elio is seated in the garden, just before being shown a fish by Anchise, there is a Sony HF cassette tape on the table which dates from around 1988. A correct one for the era could be the Sony CHF with white & orange labels on the shell.
Continuity error after Elio grabs Oliver's crotch. As shot from the front, Oliver removes Elio's hand with his left hand. Cut to the immediate continuing shot from the rear but Oliver now has Elio's hand in his right hand as he sets Elio's hand back on Elio's knee.
When Elio and Oliver are at the car preparing to head off to Lake Garda with Sam, Elio has his right foot up on the open back door panel during their conversation. However, when the shot changes to Oliver's point of view in the front seat, Elio clearly has his left foot up on the door frame. Then back outside and it's right foot again.
In the Hanukkah coda at the end of the film when Elio enters the kitchen and exclaims "Oooh, latkes!", Elio reaches down and takes two latkes from the stovetop with his left hand and exits the kitchen with the latkes in hand. Cut to Elio in the hallway outside the kitchen, no latkes in hand.
In the breakfast after the night Elio swam with Marzia, Elio was making a crepe with Nutella, the crepe had been wrapped, but next shot Elio was making the crepe with Nutella again, and next shot he took the wrapped crepe again...
When Elio shows Oliver his "secret place" he removes his sunglasses in close up just to hold them in his left hand. Camera changes to Oliver and then both of them again and the sunglasses are no longer to be seen.
On the morning after, Oliver is laying with his arm around Elio's shoulder and Oliver's bike wound almost looks healed, next scene after the swim when Oliver walks up to Elio the wound looks scabbed over again.
When prof. Perlman is showing Oliver the colour slides of Greek statues sent from Berlin, the 4th one is the 'dancing satyr' which was discovered in Sicily in 1998 (the statue is displayed in a museum specially built for it in Mazara del Vallo in Sicily), while the film is set in 1983.
In the final shot of Elio at the fireplace, a housefly can be seen crawling on his shirt. Flies don't live long enough for it to be in the house that time of year, when snow has fallen (and during Hanukkah).
Elio states at the monument for the Battle of Piave that 170,000 died there. In fact, while there may have been approximately 170,000 casualties (dead,wounded,captured ) , the total number of dead was probably closer to 20,000.
In the final scenes the Hanukkah hanukkiah is lit incorrectly for the 7th night. It is customary to place the candles on the right side of the hanukkiah. The missing 8th candle should be on the left side.
Throughout the entire movie Oliver wears a Star of David necklace. In the final scene where we see Oliver, saying goodbye to Elio at the train station, he is not clearly seen wearing the Star of David necklace. No explanation is given for why he would take it off or not be wearing it. Though it's very very hard to clasp a glimpse of it due to the way the shirt is buttoned up, there are a few split seconds where you can see the necklace is definitely on his neck during that scene.