A social services report showed there have been 120 births to girls aged 16 and under in the past 12 months.
The statistics were highlighted in a Lancashire County Council draft commissioning strategy for services for children and families.
The city is already subject to strict targets to reduce teenage pregnancies by 50% by 2010, which will involve 66 organisations and see 42 publicity campaigns.
And nearly £20,000 is also being spent on teenage pregnancy support initiatives in Preston.
Lindsay Hart was stunned when at 16 she found out she was pregnant as she prepared to take her GCSE exams.
But now five months after the birth of her son Ethan, doting mum Lindsay, a pupil of Ribbleton Hall High, has no regrets.
Now 17, Lindsay said: "My pregnancy was obviously not planned, in fact it was a really big shock, but I took it in my stride and just thought I would learn to cope.
"Everyone said I had a good head on my shoulders and they knew I would cope."
She had completed and passed all of her GCSE's before Ethan was born and has deferred her entry into college for a year.
She said: "I did plan to go to college this year, but now I am just going to go next year.
"Just because I have had Ethan it does not mean I have to put the rest of my life on hold.
"I hope to do something with hair and beauty or art."
Lindsay,17, now lives alone in Bracewell Road, in Ribbleton, Preston with her son.
But she is not isolated. She receives support from both her family and friends.
She said: "It can be hard sometimes, well it is for any mum when their baby is teething, but it is pleasure, I love being a mum.
"It can also be hard when it comes to having a social life as there is not always someone to look after Ethan. But I do get out as much as possible."
Although Lindsay has no regrets she thinks it would be useful for teenagers to get to talk to a young mum during sex education classes.
Reducing the number of teenage pregnancies is a key feature of Preston's Local Neighbourhood Renewal Strategy, which identified Fishwick, Ribbleton and Brookfield as having high conception rates.
It also said there was a lack of support for young mums which can effect the child's health and development.
It claimed single mothers increase the likelihood of children being brought up in poverty and that inadequate child care facilities prevent the mothers getting jobs.
A raft of initiatives has been drawn up, including extra school nurses, extending sex education to primary schools and expanding the Baby Think it Over scheme.