Known as Brookville Road, the highway runs 1.52 miles (2.45 km) from the District of Columbia boundary at Western Avenue to MD 410 within Chevy Chase.

MD 186 heads north along a narrow two-lane undivided street in the town of Chevy Chase Village.

MD 186 meets the northern end of Broad Branch Road just south of its third all-way stop at Primrose Street.

North of Bradley Lane, MD 186 follows the boundary between Martin's Additions and the village of Chevy Chase Section Three on the west.

The highway leaves the village and enters the unincorporated area of Chevy Chase after its sixth all-way stop at Woodbine Street.