The plant hormone ethylene influences many processes of plant growth and development. Among these control of senescence, abscission and fruit ripening ensure ethylene, its synthetic agonists and antagonists a prominent role in modern agriculture and horticulture. In the past decade molecular genetics has identified a number of signal transduction components involved in ethylene signalling and perception in the model plant Arabidopsis thaliana. Phenotype analyses emphasize that the receptors of the plant hormone have different operation modes and might trigger at least two distinct signal transduction cascades. Biochemical approaches in the past years increasingly pushed forward the characterization of interactions and functions of proteins implicated in ethylene signalling. Moreover, these studies suggest that ethylene signal transduction is more complex as anticipated by previous linear models. This correlates well with recent conclusions on the complexity of hormone cross talk demanding multiple hubs in their signal transduction pathways. In this review we integrate molecular-genetic and biochemical findings of the last decade to a consistent picture of current understanding of ethylene signalling and try to elaborate their impact on further ethylene research.