Among those arrested: A former Oregon sheriff's deputy and his wife, who is a Romanian princess.
Cock-fighting is an illegal blood sport that happens far from the eyes of the public and agents say the ring they busted Thursday was well-organized.
The raid happened just after dawn. As many as 75 local, state and federal law officers raided five different locations in Washington and Oregon.
"All these people know each other and it's a weekly event for them during the fighting season," said Agent in Charge Gary Drumheller.
Agents believe Cecilio Mendosa Magana of Kennewick is a top breeder of fighting cocks. In addition to the large breeding operation, they found medicines and syringes typically used for fighting birds.
"I'd say most of his birds probably go between $500 to probably $1,500 a piece," Drumheller said.
The federal indictment charges six people with operating an illegal gambling business, including John Walker -- a former sheriff's deputy from Oregon -- and his wife Irina Walker who is a Romanian Princess.
The indictment alleges the cockfights occurred on their Oregon ranch. Government prosecutors say Irina and John Walker staged at least 10 cockfighting derbies between April 2012 and April 2013, bringing in as much as $2,000 a day. Blades were attached to the birds' legs, spectators were charged admission, and food and drink were sold, the indictment said.
Magana is charged with criminal conspiracy to violate the Animal Welfare Act and 10 other counts of illegal animal fighting.
Agents say cockfighting is far from a victimless crime, and this ring went well beyond a simple backyard fight club.
"It becomes a very organized operation and that's where it becomes very dangerous for everybody involved," Drumheller said.
Cockfighting is outlawed in all 50 states, and though it may be acceptable in some cultures, Oregon's U.S. Attorney says aside from being a "barbaric" practice, it also jeopardizes public health and safety.
The 18 people arrested were arraigned Friday in federal court in either Portland or Yakima.
The Associated Press contributed to this report.