Scores of mums, dads, children and babies took to the streets to help raise thousands of pounds.
The fifth annual Push for Prems in Brighton and Hove in aid of the Trevor Mann specialist baby unit is expected to be the most successful so far.
Organisers are aiming to raise £20,000 from the event through online donations and sponsorship.
The walk was set up by parents of young children treated at the unit at the Royal Sussex County Hospital in Brighton as a thank-you for the care and support their children had received.
The walk started at the hospital yesterday morning, with the group then heading down to the seafront and along to Hove Lagoon.
Some were decked out in fancy dress and carried collection buckets for donations along the way to help boost funds.
When they arrived at the lagoon, the walkers released balloons before enjoying a picnic.