Epicotyl segments and nodus expiants from etiolated seedlings of Pisum sativum were transformed using Agrobacterium tumefaciens strains GV 2260 (p35S GUS INT) and GV 3850 HPT carrying either a neomycin- or hygromycinphosphotransferase-gene as selectable markers. The transgenic character of hygromycin- or kananamycin-resistant tissue was confirmed by detection of nopaline or neomycinphosphotransferase-II- and ß-glucuronidase activity in crude extracts of resistant tissues. Up to 5 % of developing shoots from shoot proliferating nodi were regenerated via organogenesis to kanamycin-resistant plantlets. Transformation frequency in vitro was found to be influenced by expiant source, A. tumefaciens strain, pea genotype and duration of cocultivation. Acetosyringone did not increase the transformation rate.