The club's greatest success was promotion to the tier-one Oberliga Nord, where it spent a single season in 1950–51.

[1][2] In post-Second World War football Itzehoer SV played in the Landesliga Schleswig-Holstein, winning three consecutive league championships from 1947 to 1950, the latter earning the club promotion to the Oberliga.

The club played, for a single season in 1950–51, in the tier-one Oberliga Nord but was immediately relegated after finishing seventeenth.

[3] From 1951 to 1965 the club played in the Amateurliga Schleswig-Holstein and, with the exception of the period from 1960 to 1962, was always a top side in the league, winning championships in 1954 and 1965.

[3] Itzehoe's most successful era came from 1965 to 1974 when it played in the tier-two Regionalliga Nord, the second tier of the German league system, below the Bundesliga.

The club, for a last time, appeared in the 1985–86 DFB-Pokal but lost 2–0 at fellow amateur side SpVgg Plattling.

[3] In 1994 Itzehoer SV became a founding member of the new Oberliga Hamburg/Schleswig-Holstein, the new fourth tier of league football in the region.