Overall, 14 teams entered this competition, the same number as in 1948, with Whitehaven being newly elected into the Rugby League at the start of the 1949–50 season, replacing the prior season's junior/amateur club entrant. No junior/amateur club took part during the 1949–50 season. The same pre-war fixture format was retained, with no bye, but one "blank" or "dummy" fixture in the first round. The second round contained one bye, but no "blank" fixture. As in the 1948–49 competition, all the first round matches were played on the basis of two legged (home and away) ties, and the remainder of the rounds on straight forward knock-out basis.
