Serving as Mayor of Tagaytay City from 1986 to 1987 and again from 1995 to 2004. While serving as the Mayor, he established the Tagaytay Public Safety Office (PSO) to manage traffic in the city. This later became the basis of policies on his transition to being the chairman of the Metropolitan Manila Development Authority (MMDA). He initiated the Character First programs that encouraged local government units (LGUs), non-government organizations (NGOs), leaders, civic and religions organizations to band together to establish a community of character with character traits of a Filipino every month.

Appointed on 2010 as the 9th Chairman of the MMDA, he launched the first Metro Manila Integrated Bus Terminal (known as the Southwest Integrated Provincial Transport Terminal or SWIPTT), as well as signed the Metro Manila Outdoor Media Magna Carta along with various advertising groups, setting the terms for regulating outdoor advertisements in Metro Manila. Prior to this, no limit had been placed on the size of advertisements, such that several billboards have served as public safety risks due to their size.

He relaunched the Pasig River Ferry System in 2014 in coordination with the Pasig River Rehabilitation Commission and the Department of Transportation and Communications.

By virtue of the Metro Manila Commission Executive Order No. 86-09, he was designated as Chairman of the annual Metro Manila Film Festival, in which he introduced a number of changes including the introduction of new contest categories and the removal of box office receipts from the criteria for selection of best picture starting from 2010.

Promoted to the rank of Brigadier General of the Philippine Army (Reserve) on March 14, 2018.

He was elected to the Philippine Senate in the 2019 elections with 15,510,026 total votes. Senator Tolentino is currently serving as a Senator of the Republic of the Philippines until 2025.