Pembrokeshire County Council has agreed to increase council tax by 12.5% for 2018/19.
The increase - thought to be the highest in Wales - represents an extra £110 a year for residents.
Despite the hike, the council still has the lowest council tax levels in Wales, and the third lowest in England and Wales.
Council Leader, David Simpson, said: ‘f we had voted for either a five of eight per cent increase in council tax - which were also options – then those services would have been badly hit, consequently affecting the most vulnerable members of our society.
‘I would remind our householders that Pembrokeshire remains one of the leanest and most productive local authorities in Wales and we actually currently deliver services at £14.8m less than the Welsh Government say we should.’