The Federal Court of Justice said Tuesday it rejected the appeal of 22-year-old Arid Uka, whose attorneys argued he should be eligible for parole after 15 years.
Uka killed two airmen and injured two others in March 2011, apparently inspired by a fake internet video purporting to show American atrocities in Afghanistan.
It was the first attack in Germany by an Islamic extremist. Uka was convicted of two counts of murder and three of attempted murder in February.
People serving life sentences in Germany usually are considered for release after 15 years, but the court ruled Uka shouldn't be, given his "particularly severe guilt."