The 24 teams were divided into six groups of four teams to play home-and-away round-robin matches. The top two teams of each group will qualify for the 2019 AFC Asian Cup, where they are joined by the 12 teams which qualified directly from the second round.
Due to the withdrawal of Guam and the suspension of Kuwait, the AFC invited both Nepal and Macau, the top two teams of the 2016 AFC Solidarity Cup, to re-enter 2019 AFC Asian Cup qualification as replacements in order to maintain 24 teams in the third round of the competition.
^ abSince the Government of Kyrgyzstan had advised them that the AFC Asian Cup 2019 Final Round Group A qualifying match between Kyrgyz Republic and Myanmar should not take place in Bishkek as scheduled on 5 September 2017 due to increased security concerns following Myanmar military clearance operations against Rohingya in August-September 2017, the AFC decided to postpone the match. On 24 November 2017, the AFC announced that the match will be played on 22 March 2018 at a neutral venue, with the Football Federation of the Kyrgyz Republic covering all the costs of the Myanmar team and of the match organisation, including airfares and accommodation. The two Member Associations will be requested to agree on the neutral venue, and if they fail to reach a consensus the AFC will make the appointment. On 12 February 2018, the Football Federation of the Kyrgyz Republic announced that the match is to be played in Incheon, South Korea.
^ abDue to the death of Kim Jong-nam that led to a diplomatic crisis between Malaysia and North Korea, the Malaysian government decided to disallow the Malaysian football team from playing in North Korea for safety reasons. On 10 March 2017, the Asian Football Confederation (AFC) announced that North Korea's home match against Malaysia, originally scheduled for 28 March at the Kim Il-sung Stadium in Pyongyang, would be postponed, with the AFC announcing on 15 March 2017 that the match would be played on 8 June. On 17 May 2017, the AFC announced that the match was postponed for a second time, to 5 October, due to "geo-political tension on the Korean Peninsula". On 28 September 2017, the AFC announced that the match was again postponed after the Malaysian government announced a travel ban on Malaysian nationals visiting North Korea. On 20 October 2017, the AFC announced that both matches between North Korea and Malaysia would be played at a neutral venue in the interests of competition fairness, with North Korea's "home" match played on 10 November 2017 and Malaysia's "home" match played on 13 November 2017.
^ abOn 15 March 2017, the AFC announced that should diplomatic relations between the two countries not return to normal, the match between North Korea and Malaysia would be played at a neutral venue, and Malaysia's home match against North Korea would also be moved to a neutral venue to preserve sporting values and the spirit of fair play. After the AFC received confirmation that Malaysians were allowed to travel to North Korea, the AFC agreed that the match would be played in Pyongyang. However, at the announcement of the second postponement, the AFC said the venue would be decided after monitoring the safety and security of the AFC Cup and AFC U-23 Championship qualifying matches taking place in North Korea in the coming months. On 20 October 2017, the AFC announced that both matches between North Korea and Malaysia would be played at a neutral venue in the interests of competition fairness, with North Korea's "home" match played on 10 November 2017 and Malaysia's "home" match played on 13 November 2017, which were later confirmed to be played at Thailand.
^ abcAfghanistan played their home matches in Tajikistan due to security concerns from the war in Afghanistan.
^ abThe Singapore - Chinese Taipei match, originally scheduled for 13 June 2017 at the Singapore National Stadium, was brought forward at the request of the Football Association of Singapore to accommodate a possible Singapore - Argentina friendly at the same location on 13 June. In addition, the game will be held away from the Singapore National Stadium due to the venue hosting a rugby test match between Scotland and Italy on the new date.
^"World Cup draw looms large in Asia". FIFA.com. 13 April 2015. Completing the [Asian Cup] tournament's qualifying contenders will be the next 16 highest ranked teams, with the remaining 12 sides battling it out in play-off matches to claim the last eight spots.