It begins at Puerto Rico Highway 2 north of central Mayagüez and runs through the municipalities of Cabo Rojo and San Germán, coming to an end in downtown Sabana Grande.

PR-102 replaces PR-64 southbound into where it runs through the Concordia Public Housing Complex until reaching a crossing at Yagüez River where it enters the industrial area immediately west of central Mayagüez.

A half mile south of the river crossing, PR-102 enters a new traffic pattern and once again becomes a six-lane divided boulevard named Bulevar Guanajibo which travels directly adjacent to the numerous public housing complexes in the area.

PR-102 continues to run south along the coastline where it enters Cabo Rojo, eventually passing through the seaside resort and fishing village of Joyuda.

Once exiting the town, the route travels a short distance through countryside until entering downtown San Germán as Calle Comercio Luna.