Bethany Christian Services stated the policy in a letter to a Jackson couple this month, and another Mississippi couple said they were rejected for the same reason last year.
"It has been our understanding that Catholicism does not agree with our Statement of Faith," Bethany director Karen Stewart wrote. "Our practice to not accept applications from Catholics was an effort to be good stewards of an adoptive applicant's time, money and emotional energy."
Sandy and Robert Steadman, who learned of Bethany's decision in a July 8 letter, said their priest told them the faith statement did not conflict with Catholic teaching.
Loria Williams of nearby Ridgeland said she and her husband, Wes, had a similar experience when they started to pursue an adoption in September 2004.
"I can't believe an agency that's nationwide would act like this," Loria Williams said. "There was an agency who was Christian based but wasn't willing to help people across the board."
The agency is based in Grand Rapids, Michigan, and has offices in 30 states, including three in Mississippi. Its Web site does not refer to any specific branch of Christianity.
Stewart told the Jackson Clarion-Ledger that the board will review its policy, but she didn't specify which aspects will be addressed.
The Web site says all Bethany staff and adoptive applicants personally agree with the faith statement, which describes belief in the Christian Church and the Scripture.
"As the Savior, Jesus takes away the sins of the world," the statement says in part. "Jesus is the one in whom we are called to put our hope, our only hope for forgiveness of sin and for reconciliation with God and with one another."
Sandy Steadman said she was hurt and disappointed that Bethany received funds from the "Choose Life" anti-abortion car license plates. "I know of a lot of Catholics who get those tags," she said.
She added: "If it's OK to accept our money, it should be OK to open your home to us as a family."
Bethany is one of 24 adoption and pregnancy counseling centers in Mississippi that receives money from the sale of Choose Life tags, a special plate that motorists can obtain with an extra fee.
Of $244,000 generated by the sale of the tags in 2004, Bethany received $7,053, said Geraldine Gray, treasurer of Choose Life Mississippi, which distributes the money.
"It is troubling to me if they are discriminating based on only the Catholics," Gray said.