AbstractEgyptian broomrape (Phelipanche aegyptiaca) is a parasitic weed causing major yield loss in many field and vegetable crops. Recent observations in Iran suggest that sesame (Sesamum indicum) may serve either as a trap crop or as a host for broomrape, depending on genotype. The central objective of this research was to identify sesame genotypes that could act either as potential trap crops, or sources of genetic material for development of broomrape resistant cultivars. Seeds of 11 Iranian sesame genotypes (Ardestan, Esfarayen, Oltan, Ahvaz, Borazjan, Darab‐14, Ferdous, Kalat, Naz Tak Shakhe, Varamin and Yekta) and 10 foreign genotypes (S16, S21, S23, S25, S4, S5, S6, S7, S8 and S9) were planted with broomrape seeds in pots. At the flowering stage of sesame, tubercle number and dry weight, shoot number and dry weight and shoot height of broomrape were determined. Shoot dry weight, root dry weight and seed yield of sesame were determined at the physiological maturity. The results showed that broomrape growth varied with sesame genotype. Egyptian broomrape dry weight measured from 1.6% (S23) to 35.4% (Kalat) of the dry weight of the sesame on which it grew. Broomrape total dry weight had positive and highly correlation with the root dry weight of the sesame genotype on which it grew. When broomrape planted with the S7, S8, S9, S21 and S23 genotypes produced tubercles, but no shoots on these genotypes. Such genotypes could be used as both trap crops and as breeding‐sources for development of resistant sesame genotypes.