At least 146 children and their parents took part in the event.
A total of 66 fish were measured, and the girl's winner of the longest fish category was Addison Conlon with her 260mm catch. The boys' winner was Jackson Aplin with a 265mm fish.
Both won fishing rods and scored a ride around the harbour on the Tauranga Coastguard boat.
Most of the fish caught were released back into the harbour.
Kidz Need Dadz trust manager Lianne Mather said the inaugural event was aimed at strengthening parent and child relationships.
"We're absolutely delighted with the response. It was really encouraging to see how people got so involved with teaching their child or children new skills and, in some cases, parents and children were learning to fish together.
"That included one parent who arrived early and stayed right to the end.
"She had spent time the day before learning how to tie fishing tackle knots so she could share that skill with her child."