During the opening attacks of the 1967 Six-Day War, Egypt lost around 100 out of about 110 MiG-21s they had, almost all on the ground; Syria lost 35 of 60 MiG-21F-13s and MiG-21PFs in the air and on the ground.
Between the end of the Six-Day War and the start of the War of Attrition, IDF Mirage fighters had six confirmed kills of Egyptian MiG-21s, in exchange for Egyptian MiG-21s scoring two confirmed and three probable kills against Israeli aircraft.
During the War of Attrition itself, Israel claimed 56 confirmed kills against Egyptian MiG-21s, while Egyptian MiG-21s claimed 14 confirmed and 12 probable kills against IDF aircraft. During this same time period, from the end of the Six Day War to the end of the War of Attrition, Israel claimed a total of 25 Syrian MiG-21s destroyed; the Syrians claimed three confirmed and four probable kills of Israel aircraft.
In September 1973, a large air battle erupted between Syria and Israel; Israel claimed a total of 12 Syrian MiG-21s destroyed, while Syria claimed eight kills scored by MiG-21s and admitted five losses.
During the Yom Kippur War, Israel claimed 73 kills against Egyptian MiG-21s (65 confirmed). Egypt claimed 27 confirmed kills against Israeli aircraft by its MiG-21s, plus eight probables. However, according to most Israeli sources, these were exaggerated claims as Israeli air-to-air combat losses for the entire war did not exceed five to fifteen.
On the Syrian front of the war, 6 October 1973 saw a flight of Syrian MiG-21MFs shoot down an IDF A-4E and a Mirage IIICJ while losing three of their own to Israeli IAI Neshers. On 7 October, Syrian MiG-21MFs downed two Israeli F-4Es, three Mirage IIICJs and an A-4E while losing two of their MiGs to Neshers and one to an F-4E, plus two to friendly SAM fire. Iraqi MiG-21PFs also operated on this front, and on that same day destroyed two A-4Es while losing one MiG. On 8 October 1973, Syrian MiG-21PFMs downed three F-4Es, but six of their MiG-21s were lost. By the end of the war, Syrian MiG-21s claimed a total of 30 confirmed kills against Israeli aircraft; 29 MiG-21s were claimed (26 confirmed) as destroyed by the IDF.