Agriculture and Livestock Development Cabinet Secretary Mithika Linturi has been ranked as the worst-performing minister.
In a report released by TIFA on Thursday, Linturi scored an E of 25 per cent.
Labour CS Florence Bore scored 31 per cent while Energy CS Davis Chirchir got 33 per cent.
Several heads of the ministries scored a mean grade of D, including Gender CS Aisha Jumwa with 39 per cent, Environment CS Soipan Tuya (37 per cent), and Mining CS Salim Mvurya (37 per cent).