| Genre: | Telenovela |
| Creator: | Caridad Bravo Adams Fernanda Villeli |
| Director: | Alfredo Saldaña |
| Starring: | Amparo Rivelles Armando Silvestre Rogelio Guerra Raquel Olmedo |
| Theme Music Composer: | John Williams |
| Opentheme: | Friends & Enemies from Eiger Sanction |
| Endtheme: | Amor de Paso |
| Composer: | John Williams, Raquel Olmedo |
| Country: | Mexico |
| Language: | Spanish |
| Num Episodes: | 125 |
| Executive Producer: | Ernesto Alonso |
| Channel: | Canal de las Estrellas |
Lo imperdonable (English: The Unforgivable), is a Mexican telenovela produced by Ernesto Alonso for Televisa in 1975. Based on an original story by Caridad Bravo Adams and Fernanda Villeli. Amparo Rivelles, Armando Silvestre and Rogelio Guerra star as the protagonists, while Raquel Olmedo and Marilú Elizaga star as the antagonists.[1]
In the year 2000, a new adaptation of Lo imperdonable was held, under the title of Siempre te amaré.[2]
| Actor | Character |
|---|---|
| Alejandra Fonseca / Andrea Reyna | |
| Mauricio Fonseca | |
| Álvaro | |
| Bertha Duval | |
| Eduardo Fonseca | |
| Gloria Fonseca | |
| Sofía Fonseca | |
| Sara Fonseca | |
| Arturo Rey | |
| Dr. Reyna | |
| Ernesto | |
| Sonia | |
| Rosalía | |
| Nelly Farca | |
| Adriana | |
| Susy | |
| Víctor Angellini | |
| Lic. Cano | |
| Alberto | |
| Héctor | |
| María | |
| Lucía | |
| Dr. Ricardo Luna | |
| Dr. Estrada | |
| Gloria (girl) | |
| Eduardo (boy) | |
| Madame Collins | |