Ms Waiguru and the 25 MCAs, opposed to her style of leadership, had been at loggerheads since last year and could not work together.
In June, the MCAs passed a vote of no confidence against the governor and impeached her but she was saved by the Senate.
Kirinyaga Governor Anne Waiguru and ward representatives have declared a ceasefire and agreed to focus on development of the region.
They made peace during a meeting held in Nairobi on Wednesday night, bringing to an end a protracted political battle that grounded operations of the county.
