The company posted earnings of $413 million or 43 cents per share, the Chicago Tribune reported Saturday. Earnings hit $554 million or 63 cents per share, in the same period a year earlier.
The jolt came from a dispute with Express Scripts, a company that manages drug benefits.
Walgreen and Express Scripts broke off doing business together this year due to a contract dispute. They have resumed their business relationship, but the split caused many pharmacy customers to take their business to rival firms, such as Rite Aid Corp. or CVS Caremark Corp, then newspaper said.
Industry analysts said the temporary split with Express Scripts may have cost Walgreen $4 billion of business.
Walgreen President and Chief Executive Officer Greg Wasson said customers were returning to Walgreen.
"They're coming back from every player. We feel good with our win-back," Wasson said in a conference call.