Waxman will replace Rep. John Dingell, D-Mich., a solid ally of Detroit automakers, on a key committee dealing with energy legislation and healthcare policy, The Hill reported Thursday.
The Washington political publication said the secret vote went Waxman's way 137-122.
The Hill called the vote a blow to the established House seniority system and a victory for Waxman's fellow Californian, House Speaker Nancy Pelosi.
Pelosi's aides denied she had lobbied for Waxman. However, The Hill said other sources were certain Pelosi had been at least rooting for him.