Kenny Shiels guide Killie to the League Cup semi-finals, beating rivals Ayr United. Despite the win, Shiels criticised rival team tactics, believing the club should have done more. On 18 February 2012, Kilmarnock beat Rangers 1–0, with Shiels' son Dean scoring in the 12th minute, making him the first Kilmarnock manager to beat Rangers twice in one season. After the match, Shiels said a win over Rangers was dedicated to the club's supporters and praised his son, who scored the only goal in the match, for his performance as "outstanding". On 18 March 2012, Shiels' Kilmarnock side travelled to Hampden Park for
Dean Shiels to join Rangers. He scored a goal, as well as, setting up two goals in his first appearance, in a Scottish League Cup tie against East Fife on 7 August. A week after he sustained an injury during a match which ruled him out for weeks, On 2 September 2012, Shiels scored his first league goal, as well as setting up a goal, in a 5–1 win over Elgin City. After scoring two goals in three games, Shiels scored against the Scottish Premier League side Motherwell, in a Scottish League Cup tie. Then, in the Scottish Cup, Shiels scored twice