In the 1966 season he achieved a few superb performances under helpful conditions, such as eight for 18 in the first innings and twelve for 49 in the match against Warwickshire at Coventry but overall the performance was disappointing in this and the 1967 season. In 1967 Jackson took eleven for 69 against Warwickshire at Edgbaston but was dropped from the Derbyshire eleven late in the season.
One match for Marylebone Cricket Club (MCC) in 1967 was his only first-class match for a team other than Derbyshire. After a poor performance in the 1968 season, Brian Jackson was not re-engaged for 1969, but he did play along with Leslie and Cliff Gladwin in a limited overs match to commemorate the centenary of the Derbyshire county club.