Rivera was the fifth Puerto Rican to win the title, which makes the island the third most successful entity in the pageant (behind the United States and Venezuela). Rivera was the third consecutive delegate from Puerto Rico to make the Top 5 at Miss Universe, after Alba Reyes placed 2nd Runner-Up in 2004 and Cynthia Olavarría placed 1st Runner-Up in 2005.

Rivera represented her hometown of Salinas municipality at Miss Puerto Rico Universe 2006, held on November 10, 2005 where she was crowned the winner by outgoing titleholder and Miss Universe 2005 1st Runner-Up Cynthia Olavarría.

From the end of July until early August, Zuleyka traveled to Japan where she presented the Five Star Diamond Award to the Mandarin Oriental Hotel in Tokyo. She also participated in a photo shoot with Kurara Chibana in San Juan, Puerto Rico and in Tokyo, Japan, the girls who became really close best friends and still keep in touch. Miss Universe Japan (and first runner-up), and Zuleyka also visited Mikimoto, the creators of her dazzling crown. In late August, Zuleyka traveled to Indonesia where she attended the opening of a new spa, met with the Minister of Culture, and attended the Miss Indonesia Universe pageant where Agni Pratistha was crowned. While in Indonesia, Zuleyka also visited Bali. On September 4, 2006, Zuleyka returned to her home, Puerto Rico for an official homecoming celebration and parade. The following day, Zuleyka returned to her hometown of Salinas.

After finishing her reign as Miss Universe, Rivera expressed her interest in an acting career. She debuted in the 2007 telenovela Dame Chocolate with Carlos Ponce and Karla Monroig. In 2010, she was offered the role of antagonist Rocío Lynch in the telenovela Alguien Te Mira. Later that year, she starred in Aurora as another antagonist, Diana del Valle.

From late 2010 to 2013, Rivera dated Dallas Mavericks point guard J. J. Barea. In July 2011, the couple announced they were expecting their first child together. Rivera gave birth to her son Sebastián José Barea Rivera in Minnesota on February 18, 2012. Barea was present during the birth.

During early 2013, there was much speculation that the relationship between Rivera and Barea had ended. However, she assured on an interview that they were still together. On April 18, 2013, Barea released a statement confirming that the relationship was over. Rivera responded with a statement of her own alleging "false information" on Barea's statement. On her statement, Rivera says that "ever since I began filming the telenovela Rosario, there weren't two consecutive weeks where I didn't travel to Minnesota, a place I considered my home, along with the father of my child." She added that she still has the satisfaction "as a woman and mother, that I gave all of me in exchange for our happiness. But this is a labor of two. Life goes on and I keep on going with my head held high."