Three pubs in the Penwortham, Leyland and Longton areas were caught selling alcohol to underage teenagers in a police sting last night.
The youngsters were able to buy vodka, gin and alcopops.
The force said the pubs concerned would be receiving a visit next week from the police and council's licensing team.
A spokesman for South Ribble Police said: "There was a joint operation last night between South Ribble Borough Council and Lancashire Police Licensing Team where we visited 14 pubs in the Leyland, Longton and Penwortham areas looking to see if they would serve alcohol to our test purchasers who are all aged under 18.
"Thanks to all the door staff and bar staff who quite rightly turned our test buyers away at the door or refused them at the bar.
"Shockingly however, three pubs sold gin and tonics, vodkas and alcopops to them and all three pubs will be dealt with in course of next week by Police and Council Licensing.
"Why would you put your licence at risk to sell a couple more drinks by not age checking young looking customers? Its not worth it."