The Asian section of the 2018 FIFA World Cup qualification acted as qualifiers for the 2018 FIFA World Cup, held in Russia, for national teams which were members of the Asian Football Confederation (AFC). 4.5 slots (four direct slots and one inter-confederation play-off slot) in the final tournament were available for AFC teams.
On 16 April 2014, the AFC Executive Committee approved a proposal to merge the preliminary qualification rounds of the FIFA World Cup and the AFC Asian Cup, which expanded to 24 teams starting in 2019. Therefore, the first two rounds of the FIFA World Cup qualifiers also acted as qualifiers for the 2019 AFC Asian Cup in the United Arab Emirates.
The qualification structure was as follows:
The 46 FIFA-affiliated nations from the AFC entered qualification. In order to determine which nations would compete in the first round and which nations would receive a bye through to the second round, the FIFA World Rankings of January 2015 were used (shown in parentheses), as those were the latest published rankings prior to the first round draw. The FIFA Rankings of January 2015 were also used for seeding of the first round draw; however, for seeding in the second round and third round draws, the most recent FIFA Rankings prior to those draws were used.
This was the first effective participation of Bhutan, the country registered for the qualifications of 2010 but withdrew without playing a game (initially drawn against Kuwait in the first round).
The schedule of the competition was as follows.
The draw for the first round was held on 10 February 2015, 15:30 MST (), at the AFC House in Kuala Lumpur, Malaysia.
The draw for the second round was held on 14 April 2015, at 17:00 MST (), at the JW Marriott Hotel in Kuala Lumpur, Malaysia.
To determine the four best runner-up teams, the following criteria were used:
As a result of Indonesia being disqualified due to FIFA suspension, Group F contained only four teams compared to five teams in all other groups. Therefore, the results against the fifth-placed team were not counted when determining the ranking of the runner-up teams.
The third round consisted of two groups of six teams. The first two teams in each group qualified for the 2018 FIFA World Cup. The two third-placed teams proceeded to the fourth round.
The draw for the third round was held on 12 April 2016, at 16:30 MST (), at the Mandarin Oriental Hotel in Kuala Lumpur, Malaysia.
The two third-placed teams in each group from the third round played against each other home-and-away over two legs to determine which team advanced to the inter-confederation play-offs.
The order of legs was announced during the draw for the third round. Syria played their home match, as with all their home matches in the third round, in Malaysia due to the war time condition in Syria.
The draw for the inter-confederation play-offs was held as part of the 2018 FIFA World Cup Preliminary Draw on 25 July 2015, starting 18:00 MSK (), at the Konstantinovsky Palace in Strelna, Saint Petersburg. The fifth-placed team from AFC was drawn against the fourth-placed team from CONCACAF, with the AFC team hosting the second leg.
The following five teams from AFC qualified for the final tournament.
Below are full goalscorer lists for each round: