The Asia/Oceania Zone was the unique zone within Group 4 of the regional Davis Cup competition in 2018. The zone's competition was held in round robin format in Muscat, Oman, from 29 January to 3 February 2018. The two winning nations won promotion to Group III, Asia/Oceania Zone in 2019.
Format: Round-robin basis. Two pools of six teams. The winner of Pool A will play-off against the runner-up in Pool B and the winner of Pool B will play-off against the runner-up in Pool A to determine which two nations will be promoted to Asia/Oceania Zone Group III in 2019.
Standings are determined by: 1. number of wins; 2. number of matches; 3. in two-team ties, head-to-head records; 4. in three-team ties, (a) percentage of sets won (head-to-head records if two teams remain tied), then (b) percentage of games won (head-to-head records if two teams remain tied), then (c) Davis Cup rankings.