Between 3.45pm and 4.30pm on June 29, the victim was riding her mobility scooter on a pathway between Marsh Way and Pope Lane, Penwortham.
The woman had a shopping bag on each handlebar.
As she continued on the pathway, she was approached by three teenage boys riding bikes.
One of the group cycled towards the victim and snatched a shopping bag from the right handlebar, before a second teenager attempted to take the second bag of shopping.
The 72-year-old woman managed to stop the second bag from being removed before the group cycled off.
The offenders are all described as white, of slim build, aged 17, with short dark hair wearing dark clothing.
Police are appealing for information following the theft and are keen to speak to anyone who witnessed the incident.
PC David Gelson, of Lancashire Police, said: “This was a particularly appalling and despicable theft.
“The incident has left the victim extremely upset and she remains shaken by her ordeal.
“We are keen to find those responsible and would ask anyone who saw or heard anything to contact police.
“We understand the area is popular with dog walkers and would appeal to anyone with information to contact us immediately.”
If you can help, contact police on 101 quoting crime reference SA1608583.