Gabrielle Medina, the daughter of a wealthy Argentinean rancher, arrived in Llanview in 1986. She had given her virginity to rascal Max Holden, believing that he wanted to marry her. Instead he dumped her, and she had to pass their love child, Al, off as Tina Roberts' son. The truth eventually came out and Max began raising him as his son. Gabrielle and Max were passionately in love, but Gabrielle married his brother, Steve. Steve was killed by a bomb in a wedding cake, and after saving her from joining a convent, Max and Gabrielle married.

After Max was presumed dead in a car wreck, Gabrielle fell into an affair with married, devious Michael Grande. During an argument with his pregnant wife, Alicia, their car crashed. Alicia died soon after giving birth. Michael was devastated. Gabrielle went to see Michael's baby in the nursery, and sadly, the child died. To spare Michael even more grief, Gabrielle switched his baby with Brenda Brock's baby. At the culmination of this story, Gabrielle was locked up, and then given community service. Soon after, Max came back with a new face. Gabrielle resumed their relationship, but also seduced a hunky priest, Father Tony Vallone. Local mob boss Carlo Hesser videotaped their tryst and blackmailed Gabrielle into poisoning Viki. Gabrielle couldn't go through with it. When she was arrested, Gabrielle planned to tell the court of Carlo's plans, but after he threatened to kill Al, Gabrielle stayed silent. She was sent to prison for nearly 7 years, until she was released in 1997. Max sent Al to live with her.

She returned to Llanview in 2001, planning to get revenge on Max Holden for letting her suffer in prison and for skipping out on paying her any child support for Al. She married Asa Buchanan to help him in his plan to frame Max for murder. Asa asked her to pretend to love Max and have an "affair" with him. As she did, she rediscovered her old feelings for him and Max began to like her again. Gabrielle began to wonder if really killing Asa wasn't such a bad idea after all. Asa, however, beat them to it. After faking his own death, Bo thought Max and Gabrielle had done it. Neither of them did, of course, so they planned on escaping. They went to Saint Blazes Island where they discovered the real live Asa. Asa was arrested and Max and Gabrielle were free. But Max discovered that Gabrielle had planned on framing him for Asa's "murder" originally, and wanted nothing to do with her. They eventually reconciled their friendship before Max left town in fall 2003.

After Asa kicked Gabrielle out, Bo let her move into his apartment so he could keep an eye on her. One evening, Gabby overheard Todd Manning talking to David Vickers on the docks about giving away Blair's real baby and then bringing it back as an adopted child. Gabby used this to her advantage and blackmailed Todd into giving her a job as style editor at the Sun. Gabrielle tried to use her salary to help pay off Al's hospital bills (he was accidentally pushed off a cliff by Cristian Vega). Asa attempted to manipulate Gabrielle into taking a payoff, but Gabrielle alerted Bo and they busted Asa. Bo made Gabrielle calmer and more loved, while Gabrielle made Bo feel young and excited. They became lovers.

Several months later, Gabrielle found a letter from Sam Rappaport which revealed that Bo was the father of his ex-wife Nora's young son, Matthew. Gabrielle kept quiet for a few weeks, even stealing another copy of the letter from Nora's house, but finally came clean. Bo forgave her, and they were truly happy until fall 2003, when Al came down with a serious infection. Gabrielle donated a kidney, but nothing could save him. Destroyed, she began drinking and no longer felt worthy of love. Gabrielle was finally starting to enjoy life again as the New Year dawned. She accepted Bo's marriage proposal and put Al's death behind her. Unfortunately, at a party to ring in 2004, Gabrielle was left alone for a few moments. The Music Box Killer snuck up on her. Before she could react, he snapped her neck. Bo found her and held her lifeless body in his arms. He and all of Llanview mourned the loss of a vibrant, passionate, deeply caring woman who died far too young.

In 2012, after a prison break where all the Llanview felons escaped, the spirits of Gabrielle, Luna, and Megan happily witnessed the final death of Mitch Laurence. Then the trio of spirits watched over Cole Thornhart after he had been shot by Hannah O'Connor, and sent him back with work undone from heaven's door. Next, Bo Buchanan arrived at heaven's door after he had been shot by Troy MacIver. They told Bo it was his time, but Bo resisted and returned to Viki alive. Then they met Viki at heaven's door after she had been shot by Allison Perkins. But Viki decided it was not her time, and went back to Llanview still alive.