The suggestion that ethylene plays a role in the transition from vegetative growth to flowering started with the observation of the promoting effect of fire smoke on flowering of pineapples. That idea was rapidly confirmed for the bromeliads with the use of ethylene analogs, precursor, inhibitors of biosynthesis and measurements of ethylene release. In the long-day rosette plant spinach, we found in the 1980s that there was a burst of ethylene release when plants were induced to flower by long days, but not when they were induced by gibberellin application (7, 8). The identification in Arabidopsis in recent years of several independent genetic pathways promoting flowering, together with the discovery that gene ACS10 related to ethylene biosynthesis is specifically up-regulated by activation of the long-day promotion pathway, have shed a new light on our physiological observations in spinach. In addition, recent work with Arabidopsis mutants of the ethylene transduction pathway demonstrated that ethylene sensitivity is required in wild-type plants for a normal flowering time. New doors are by the same occasion opened for the understanding of ethylene cross-talkings with other regulators (auxin, polyamines, jasmonate) and nutritional metabolites (glucose, sucrose) involved in the control of flowering.