In 1965 the professional team of De Boys merged with their rivals Sportclub Enschede to FC Twente (both clubs continued in non-league football).

However, in a poule with AFC Ajax, Blauw-Wit Amsterdam, sc Heerenveen, SV Limburgia and Maurits they ended last.

When in 1954 professional football was introduced in the Netherlands and the regional system disappeared, Enschedese Boys had to start in the Tweede Divisie (3rd tier), while local rivals Sportclub and vv Rigtersbleek could start respectively in the Eredivisie (highest) and Eerste Divisie (2nd tier).

Since both De Boys and Sportclub had financial problems and the city Enschede only wanted to help one team, both clubs merged in 1965 to form FC Twente '65.

In season 1974/75 the club moved to their current ground Sportpark Wesselerbrink Zuid in the new south district of the city.