During his 4-year mayoral term, Zayas Seijo established the Mariana Suárez de Longo Library and Historical Archive of Ponce, the Museo del Autonomismo Puertorriqueño, the Centro Ponceño de Autismo[1][2] (English: Ponce Center for Autism), the Agüeybaná II "El Bravo" Plaza, and also expanded the Julio Enrique Monagas Family Park.

He was, however, instrumental in the development of the Parque Lineal Veredas del Labrador,[3][4] as well as the Río Portugués Dam and the expansion of the Ponce Municipal Police.

When he was 16 years old, Zayas Seijo enrolled at the College of Agriculture and Mechanical Arts of Mayagüez where he obtained a bachelor's degree in agronomy.

That year, his uncle, Humberto Zayas Chardón, retired from politics and vacated the seat he occupied in the Puerto Rico House of Representatives.

On 4 November 2008, Zayas Seijo lost the election to the candidate of the New Progressive Party, María "Mayita" Meléndez Altieri and was succeeded on 2 January 2009.

In October 2008, Zayas Seijo inaugurated Plaza Agüeybaná II "El Bravo" at the intersection of PR-123 and PR-2 in the Caracoles sector of barrio Playa, Ponce.

Zayas Seijo is also credited with expanding the Julio Enrique Monagas Family Park in October 2008, and with the establishment of the Centro Ponceño de Autismo during his tenure.