Interspecific cross between Nicotiana trigonophylla and N. tabacum cv. BY4 is highly sterile because of abnormal ovule and embryo development. In vitro culture of excised N. trigonophylla ovules after polination by N. tabacum allows significant numbers of hybrid embryos to develop into mature plants. Total yield of seedlings and number of normal seedlings were produced following in vitro culture of individual fertilized ovules of N. trigonophylla X N. tabacum at four days post-pollination on B5 medium containing 6% sucrose. Hybrids were uniform in morphology and peroxidase isozyme composition and the majority were cytologically stable: flower characteristics were generally intermediate between those of the parents. All hybrids evaluated were self-sterile.