The Boy Scouts of America lost over 6% of its membership in the past year, after voting to allow openly gay scouts but keep a ban on gay scout leaders.
The total BSA membership has fallen to just 2.5 million youth members and 960,000 adults.
According to Smith, the organisation does not keep track of how many of those groups may have left the organisation over the decision to allow gay scouts, or over the decision to keep the ban on gay adults.
He added: “Our membership policy is that we do not ask people about their sexual orientation, and it’s not an issue until they deliberately inject it into scouting in an inappropriate fashion.
“Nor do we act on hearsay, allegations of belief or reports of past activities.”