In 2010, Cayetano finally decided to enter into politics as a barangay captain of
Fort Bonifacio. He was later elected as congressman of
Taguig's 2nd district in
2013 at the age of 36, and under the
Nacionalista Party. In his first days in office, Cayetano filed the "Iskolar ng Bayan" bill, that first implemented in the city. In the bill, all graduates and Top 10 of their classes from high schools automatically become scholars in state-owned universities including the
University of the Philippines. Three years later, he filed the certificate of candidacy to seek a reelection as representative in
2016, but he decided to withdraw to give way to his sister Pia as his replacement. Pia eventually won the race. As mayor, he supported President
Rodrigo Duterte, calling himself a "certified "
DDS". In 2024, he filed his candidacy to run for representative of
Taguig–Pateros's 1st District in the
2025 Philippine general election. Among his campaign promises was the creation of a third congressional district for Taguig representing the
Embo barangays, which were then
newly-transferred to Taguig from
Makati. However, on October 30, the Election Registration Board (ERB) of the
Commission on Elections (Comelec) in Taguig rejected Lino and Fille Cayetano's application to transfer their voter registration to Taguig's 1st district, citing unmet residency requirements. He ran under the BIDA TAYO ticket, opposite to Lani Cayetano's Team TLC. However, he lost the race to incumbent Representative Ricardo "Ading" Cruz Jr., who was once his vice mayoralty running mate in 2019. In October 2025, Cayetano made a statement toward remarks made by his brother, Senator
Alan Peter Cayetano, proposing for a mass resignation from the Philippine government and holding a snap election amidst the
flood control projects controversy: "I agree with my brother Alan and ask that we start with ourselves. Give up power[....] If you truly believe what you say, then trust and have faith that if some of the old guard step down now – it will inspire others to follow. I will support further that no Cayetano should run in 2028." ==Personal life==