During the 1980s, then Peruvian president Alan García proposed what was supposed to be a radical restructuring of the political and economical divisions of the country: regionalization. The law, which was approved, mandated the creation of regions to function eventually as autonomous economic and administrative entities; 12 regions were formed from 23 of the former 24 departments. Formation of another region was delayed by the reluctance of the Constitutional Province of Callao to merge with the Lima Department. Originally San Martín and La Libertad Regions formed the sole region of San Martín-La Libertad but later were split.
The regions had to assume major responsibilities because of inadequate funding from the central government, and organizational and political difficulties. This political division was never successful, and its implementation was cancelled.
| Region | Departments forming the Region | |
|---|---|---|
| Amazonas Region | Loreto Department | |
| Andrés Avelino Cáceres Region | Huánuco Department (except part of Marañón Province and Leoncio Prado Province), Pasco Department and Junín Department | |
| Arequipa Region | Arequipa Department | |
| Chavín Region | Ancash Department (plus part of the Marañón Province and Leoncio Prado Province of the Huánuco Department) | |
| Grau Region | Tumbes Department and Piura Department | |
| Inca Region | Cusco Department, Madre de Diós Department and Apurímac Department | |
| La Libertad Region | La Libertad Department | |
| Los Libertadores-Huari Region | Ica Department, Ayacucho Department and Huancavelica Department | |
| José Carlos Mariátegui Region | Moquegua Department, Tacna Department and Puno Department | |
| Nor-Oriental del Marañón Region | Lambayeque Department, Cajamarca Department and Amazonas Department | |
| San Martín Region | San Martín Department | |
| Ucayali Region | Ucayali Department |