Neil made her Argentine television debut on Telefé's production Verano del '98, playing a small role, in 1998. She acted alongside Celeste Cid, Guido Kaczka and Diego Mesaglio, among others. Neil was then cast as "Martina" by Alberto Fernández de Rosa in Cris Morena's Chiquititas, an international hit. Neil joined Cid, Kaczka, Fernández de Rosa and Mesaglio in that production, and she played Valeria Díaz's romance rival and Ezequiel Castano's "Mosca"'s love interest. In 1999, Neil played a second character in Chiquititas, as "Fernanda". Neil met Romina Yan, Luisana Lopilato, Georgina Mollo and Camila Bordonaba as a member of the Chiquititas cast. She debuted in the same episode that Patricio Schiavonefirst appeared; "Martina" and "Patricio" came from the same orphanage home before arriving at the so-called "Rincón de Luz" orphanage home. After her participation in Chiquititas was over, Neil took a break off acting and began a career in modeling. In 2001, however, she returned to Argentine television, alongside Yan, Puerto Rican singer Chayanne and Araceli González in Provócame, which was shown on English speaking countries as "Savage Attraction". Neil played "Erica Villalobos Kent de Parisi" in that soap opera. Provócame also became an international hit, although not as significant as Chiquititas had been. In 2002, she was reunited with fellow former Chiquititas stars Bordonaba, Lopilato, Mollo, Felipe Colombo and Diego Mesaglio, among others, in Rebelde Way. Neil played "Fernanda Peralta Ramos". After acting inRebelde Way, Neil worked in Floricienta, Doble Vida and concentrated on her modeling career. In 2006 she played Fernanda Linares Pacheco, most known as Fer, in the soap-apera called El Refugio. Neil, along with Francisco Bass, Piru Saez, Jorge Maggio "Coco" and her friend Belén Scalella, worked in this soap opera during one year and had a group called Rolabogan, which was also part of the soap opera's theme. The second season of this soap opera was mentioned by Piru Saez and María Fernanda Neil would appear in it again. After appearing in La Ley Del Amor, she appeared in Gran Hermano Famosos, the Argentine version of Celebrity Big Brother.