Sales were $114.83 billion, down a scant 0.1%
Wal-mart posted higher revenues at namesake US stores, but sales dropped in both international operations and at its wholesale chain, Sam's Club.
Operating and administrative expenses rose 2.8% to $22.7 billion.
In addition to higher wages for US staff, WeL-mart has boosted spending on commerce investment.
"We had a solid first quarter," said chief executive Doug McMillon. "We need to continue to get better at consistently running great stores, clubs and e-commerce everywhere we operate ... and we are.