On February 21, 1998, Mosisili was elected leader of the LCD after Mokhehle chose to step down due to poor health.

In the ensuing debacle which saw the army, police and king complicit in an attempt to unseat his government, Mosisili had to resort to asking the regional grouping, Southern African Development Community (SADC), for an intervention to stem the imminent coup.

To this end, joint force, consisting of South African and (later) Botswana troops, entered Lesotho on September 22, 1998, to put down the mutiny and restore the democratically elected government.

On Mosisili's advice, King Letsie III dissolved parliament on November 24, 2006, and a new election was scheduled for February 17, 2007; they had previously been expected in April or May.

[12] Whilst attending a funeral in his home district of Qacha's Nek in late 2006, Mosisili gave a speech which quoted a Basotho idiom, "Se sa feleng sea hlola", meaning "anything that does not finish/end is not good".

[13] Six people appeared before a South African court in July 2009 on charges of helping in the attempt.

[16] The election was held on 3 June 2017 and resulted in a victory for Tom Thabane and his party, the ABC, which won 48 seats against 30 for Mosisili's Democratic Congress.

[17] A government statement on 8 June said that Mosisili had submitted his resignation to King Letsie but would continue in a caretaker capacity.