The Office of the Sergeant-at-Arms is responsible for the security and maintenance of order in the Senate in accordance with the orders of the Senate President or Secretary. It provides physical and logical security for the members of the Senate and their staff, offices of the Secretariat and all properties located within its premises.

Security Enforcement Service is responsible for the implementation of security rules and regulations of the Senate, vis-à-vis the protection of the Senators, Senate employees, guests and all properties found therein. It coordinates with other government agencies when the need arises in the implementation of security measures. Aside from the physical security, the SES maintains a round-the-clock communications network. It also has a CCTV surveillance system for electronic monitoring.

Security Support Service is the administrative arm of the Office of Sergeant-at-Arms. It is responsible for policy drafting and review; administrative disciplinary investigation; subpoena and warrant service; logistics and supplies; legislative paging; ID design and issuance; and OSAA training and welfare.