SummaryUnder field conditions a wildDaucusspecies from Libya,D. capillifolius, supported less than one tenth as many carrot flies (Psila rosae) as the susceptible carrot cultivar Danvers Half Long 126. Breeding lines developed from crosses betweenD. capillifoliusand three different carrot types were grown in a series of field experiments at Wellesbourne between 1980 and 1989. Each year selections were made for agronomic quality and/or for increased resistance to carrot fly. The programme produced lines which for size, shape and colour represented most of the commercially‐important carrot types. Some of these lines were also significantly more resistant to carrot fly than selections from the partially‐resistant cv. Sytan. However, the best lines were not as resistant as the wild parent. The highest quality resistant lines were sold to seed companies for variety product