The Supreme Court on Monday let stand a lower court's ban on therapy intended to change the sexual orientation of gay youths under the age of 18.
The justices declined to hear the case, King v. Christie, without comment.
In so doing, they left in place a New Jersey appeals court's decision to uphold a ban on so-called "gay conversion therapies."
The ban was initially was signed into law by New Jersey governor Chris Christie, and challenged by therapists and Christian groups that championed the counseling.
The top court in June 2014 had declined to rule on a similar ban on gay therapy in California.
The American Psychiatric Association in 1973 concluded that homosexuality was not a mental disorder that could be treated with therapy.
The ruling comes as the top court is in the midst of deliberations over whether same-sex couples have a constitutional right to marry in the United States.
In a separate case, the court also declined to take up a prisoner's suit for the right to sex-change surgery. It did not explain its decision.
The court's order effectively denied the right to sex-reassignment surgery to a Massachusetts inmate serving a life sentence for the murder of his wife.
Michelle Kosilek, formerly Robert Kosilek, sued after Massachusetts state prison authorities refused him the surgery.