Among the patients were two children, Željko Kaštelan, head of the hospital's urology clinic, told a press conference.
The hospital's deputy director, Milivoj Novak, said 99 transplants were performed in 2019, 88 in 2021 and 106 in 2022.
The head of the hospital's clinic for cardiovascular diseases, Davor Miličić, said Croatia began doing heart transplants 35 years ago.
"With ten transplants per million inhabitants, Croatia is first in Europe," he said, adding that the UK has 2.4 transplants per million, while Spain and France have five or six.
The hospital officials said they were especially proud of a simultaneous heart and liver transplant on the same patient earlier this year, describing it as a rarity in world terms, with the organs obtained from two donors via Eurotransplant and about 100 people involved in the whole process.
The transplantation system is well-organised, said Jasna Brezak, head of KBC Zagreb's transplantation and explantation department. "The fact that Croatia is near the top in the world in the donor and transplantation programme shows that our medicine is at a totally enviable level."