Milkins reached the second ranking event semi-final of his career in the 2012 World Open. He qualified for the tournament with 5–1 and 5–0 wins over Sam Craigie and Ryan Day respectively. He was required to play in a wildcard round once at the event in Haikou, China, where he beat amateur Thanawat Thirapongpaiboon 5–3 to set up a first round encounter against Stephen Maguire which Milkins won by another 5–3 scoreline.&lt;ref name="2011/12"&gt;&lt;/ref&gt; He defeated Jin Long 5–2, before dispatching reigning world champion John Higgins 5–3 in the quarter-finals. However, Milkins lost his last 4 encounter with Stephen Lee 2–6 and admitted after the match his performance levels had dropped from his previous displays in the tournament. Milkins also reached the second round of the Shanghai Masters and the first round of the UK Championship during the 2011–12 season and made a 147 break in the qualifying stage of the World Championship. He finished 2011/12 ranked world number 36.