Sierra Madre established its historic preservation program in 1987 with the adoption of a historic preservation ordinance.  However, in 1997, the City amended the ordinance language to make landmark designation voluntary for property owners, and the following year placed a measure on the ballot to de-list 29 landmarks.  Preservation advocates countered with a legal case and the California Supreme Court issued a ruling that barred cities from stripping buildings of historic landmark status without environmental review.

Owner consent remains a requirement for landmark designation, but the City has adopted historic preservation incentives, including the popular Mills Act property tax abatement program and the waiver of city permit and plan check fees for owners of local landmarks.

The City had a dedicated historic preservation commission, but it was disbanded as a reviewing body in 2002, with the Planning Commission currently sitting in that capacity.