Wednesday's decision rejects a lawsuit filed by several animal-rights groups.
The National Park Service plans to begin the nighttime hunt next month.
U.S. District Judge Mitchell Goldberg says it's clear the park is overrun with white-tail deer, causing damage to the park's vegetation and habitat.
Goldberg says there's no evidence the park service decision was capricious or arbitrary.
Animal-rights activists say the park should be maintained by natural means.
The 3,500-acre park is about 20 miles west of Philadelphia.