Smith lost the first two sets of his first round match against Ronny Huybrechts at the 2015 World Championship without winning a leg. He went two nil up in legs in the next set but missed a total of five darts for it to be beaten 3–0. He was unable to get past the last 16 of any event in 2015 and dropped out of the top 32 on the Order of Merit during the year, which meant he failed to qualify for the World Championship for the first time since the 2005 event. He lost 6–5 in the first round of the 2016 UK Open to Jermaine Wattimena. Throughout 2016 he failed to progress beyond the last 32 of a single tournament. He was the world number 74 after the 2017 World Championship and entered Q School to try and win his place on the tour back. One last 64 finish during the four days of play was not enough to do so, and Smith only had a limited selection of events to enter in 2017.