Two customers found the metal in packets of the vegetables in Manchester and Glasgow stores.
The Food Standards Agency issued a warning for the affected products, which are the supermarket’s 170g bags of the beans with display until dates of 22 April, 23 April and 24 April.
A spokeswoman for Morrisons said an investigation was under way.
Customers who have bought the product should return them to the Morrisons branch where they were purchased to receive a full refund, the supermarket said.
Morrisons said the police had been informed of the two incidents.
It added: “We have been made aware of two incidents involving metal being found in two packets of green beans.
“The health and safety of our customers is our top priority, so as a precaution, we are recalling the products and are continuing with our investigation.
“The relevant authorities have been informed and we are also talking to the two customers.”