The pass has been historically important to Asturias as the lowest elevation direct route between the capital, Oviedo, and the rest of inland Spain via Léon.

The pass delineated, for a time, the frontier between the Christian Kingdom of Asturias and the Moorish extent of the Umayyad Caliphate.

The importance of the pass has diminished in recent years as the N-630 highway has been supplanted by the A-66 freeway which bypasses Puerto de Pajares through the Negrón Tunnel since 1997, 6 km (3.7 mi) to the west.

In addition, a 25 km (16 mi) long railway tunnel bypassing the pass, the Pajares Base Tunnel, was opened in November 2023 as part of the León-Asturias High Speed Line, after 18 years of construction and several delays due to leakage issues.

There is a restaurant located at the summit of the pass offering views in both directions.