Cyclohexylamine and methylglioxalbis(guanylhydrazone), inhibitors of polyamine synthesis, when added to the germination medium of Cicer arietinum L. seeds, increase the germination percentage and ethylene level in both control (25°C) and thermo-inhibited seeds (30°C). This stimulation is inhibited at higher temperatures (35°C), ethylene is not produced and putrescine and spermine are accumulated, both in free and bound forms. The inhibition of the biosynthetic pathway or action of ethylene by norbornadiene and CoCl 2 not only causes an important accumulation of free and bound polyamines, but also prevents germination. In the seed response to aminoethoxyvinylglycine, both biosynthetic pathways are altered. The physiological implications of the distribution of S-adenosylmethionine is discussed in relation to the importance of ethylene synthesis in Cicer arietinum seed germination.