Angel Locsin was the original producers' choice to play the title role. But her busy schedule forced her to refuse the offer since she is set to go to London to study fashion design. Further, Angel reasoned that the series needs the lead character to sing and dance she can't do.
Angel Locsin refusal to audition for the lead role sparked the feud between the actress and her home studio, she wanted to role offered to her. Angel and her manager Becky Aguila left the network and signed up to rival ABS-CBN.
MariMar's two-hour finale hit 52.6% according to AGB-Nielsen in Mega Manila. It registered a 57.5% rating for non-cable. This beats the record set by Darna in 2006 who got 52.1% making MariMar, the highest rating primetime drama in the Philippines to date.
The finale episode of MariMar was aired on March 14, 2008. The two-hour finale highlighted the tying of the knots of Sergio Santibanez (played by Dingdong Dantes) and MariMar Aldama (Marian Rivera). The wedding was held at the historic San Agustin Church. The reception of the wedding in the finale was aired live in Studio 3 of GMA Network.
Priominent persona in the industry graced the Santibanez-Aldama Wedding like beauty guru Ricky Reyes, young entrepreneur Tim Yap, Master Showman German Moreno, Regal Films producer Mother Lily Monteverde, executive producer Wilma Galvante, GMA Films president Annette Gozon-Abrogar and talent manager Douglas Quijano were sponsors. Regine Velasquez and Ogie Alcasid were the wedding singers. Other celebrities like Rufa Mae Quinto, German Moreno, Sandy Talag, LJ Reyes, Arci Munoz took part in the wedding entourage. It was earlier announced big personalities and politicians like Imelda Marcos and Jinggoy Estrada were earlier invited as sponsors, but the network decided not to pursue because of political reasons.
A finale TV special entitled "MariMar: Isang Pasasalamat" was aired on March 9, 2008 prior to the finale week of the show. This is the second time that GMA Network made a farewell special, the first was for Encantadia. It got a 19.9% rating which is the second highest for that date according to AGB-Nielsen. Due to insistent public demand, the special, retitled "MariMar Memories" was re-aired on March 16, 2008 and it got an impressive 28.4% rating.
Due to the phenomenal success of MariMar, the management decided to give Dingdong Dantes and Marian Rivera a follow-up project which is the TV serialization of Filipino mermaid legend _'Dyesebel (2008)'_.