The 1978 King Cup was the 20th season of the knockout competition since its establishment in 1956. Al-Ahli were the defending champions and successfully defended the title, winning their second one in a row. Al-Ahli beat Al-Riyadh who became the first First Division side to reach the final.
By winning both the 1977âÂÂ78 Saudi Premier League and the 1978 King Cup, Al-Ahli became the first Saudi team to achieve the domestic double.
Source: Bracket
The matches of the Round of 32 were held on 30 and 31 March 1978.
The Round of 16 matches were held on 5 and 6 April 1978.
The Quarter-final matches were held on 11 and 12 April 1978.
The four winners of the quarter-finals progressed to the semi-finals. The semi-finals were played on 16 April 1978. All times are local, AST ().
The final was played between Al-Ahli and Al-Riyadh in the Youth Welfare Stadium in Riyadh. By reaching the final Al-Riyadh became the first First Division side to reach the final. This final was a repeat of the 1962 final which ended in a win for Al-Ahli.