Several of the supporting characters in the film are based on real people who experienced the Videla era and Pinochet's 1973 coup. Neruda's then-wife Delia del Carril lived to be 104 years old, and died in 1989: the comment in the narration about her possibly living another four decades was accurate. Her house in Santiago (164 Avenida Lynch) is now a museum and cultural center. Alvaro (Alvaro Fernando Jara Hantke) who organized the effort to hide Pablo and Delia, was then a student in his twenties - he later became a respected historian, dying in 1998 at age 75. Victor (Victor Pey), the young Spanish-born engineer who offered his small apartment as a hiding place for the couple, helped copy and distribute Neruda's work - he survived until 2018, age 103.
Although the director insists that he was making an "anti-biopic" that wasn't focused on historical accuracy, many details in the film are described in Adam Feinstein's 2004 biography of the poet. Neruda did love dressing up in costumes and reading pulp crime fiction. The collections of butterflies, seashells, and marine artifacts in the movie are very similar to the ones in his actual dwellings. He hand-wrote his poems in green ink (the bottle is visible in the film, as is the inscription he leaves in a book for his pursuers). The "fish stew" mentioned in the narration was one of Neruda's favorite recipes: he wrote "Oda al caldillo de congrio" ("Ode to Conger Chowder") about it. Feinstein (Ch. 9) notes that the border police did turn Neruda back because some of his documentation showed his original name. Delia's complaint about washing dishes, and Victor presenting her with rubber gloves, are true. It's also true that Pinochet, a young officer back then, was put in charge of the Pisagua concentration camp. Three hundred agents really were assigned to Neruda's case. The Videla government did bring Neruda's ex-wife Maruca over to accuse him of bigamy, though not until 1952 after his return from exile in Europe. She did ask for a million pesos, but settled for 300,000. She was furious to see a wall inscription proclaiming him to be a traitor, and said that she wanted to erase it.
Official submission of Chile for the 'Best Foreign Language Film' category of the 89th Academy Awards in 2017.
According to lead actor Luis Gnecco on the DVD commentary, his scene in the brothel with the trans singer (played by Roberto Farías) was partially improvised. Gnecco didn't know exactly what was going to happen and was a bit nervous, and when Farías begged Neruda to recite one of his most famous poems, Gnecco tried to respond in character but couldn't remember all the lines. Farías saw his predicament and abruptly leaned in to kiss him, interrupting the recitation. Neruda's self-deprecating laughter afterwards is real.
Victor is seen depositing copies of Neruda's poems in old-fashioned red mailboxes around the city. Director Pablo Larraín revealed that they had only made one replica box, and moved it from scene to scene, repainting it and adding touches like anti-Neruda posters to make it look slightly different each time.