Thursday night has become a popular student night in the city – but schoolchildren are also flooding into bars.
The number of youngsters out drinking has become so notorious it has been dubbed as "nappy night" by bouncers and police.
A clampdown on bars serving drinks to minors is now under way after a girl of just 13 was arrested for being drunk and disorderly in the city centre.
The 13-year-old – found intoxicated by police patrolling city centre streets – went on to identify which pubs had served her alcohol and which had refused entry.
Police are urging parents to keep a track of their children – and are warning pub bosses they will be prosecuted if they are caught serving drink to anyone under 18.
Pc Mick Butler said he was also very concerned that children dressed as adults could be putting themselves at risk after the rape of a 16-year-old, who was drinking in the city centre last month.
Pc Butler added: "It is not just the risk they could be arrested that parents should be concerned about. They could be attacked. It is time parents made sure they are aware of where their kids are."
Sunderland police are waging a war on under-age drinking as part of Operation Gryphon – their crackdown on antisocial behaviour.
Off-licences are being staked out, parks patrolled and booze seized and poured down the drain by police.
Police will now also be focusing their efforts on the city centre, working closely with doorstaff and licensees to try and prevent under-age drinkers being served.
Pc Butler said "There has always been a problem with under-age drinking in the city centre and we are working closely with Pubwatch members to stop them serving.
"I often get phone calls from parents asking whether there is a teenage disco because their children are trying to hoodwink them into letting them drink in the city centre.
"I would urge all parents to make sure their kids are not drinking in the city centre by making sure they know exactly where they are if they are not at home in the evening."