This special issue re-states the basic principles of the System of Rice Intensification (SRI), reports on its evolution and expansion and deals with aspects that are still misunderstood or are in contention. SRI represents a paradigm shift from the traditional belief that rice is best produced under continuously flooded conditions to recognition of the benefits of producing rice in an aerated soil. The essential components are planting single, 8–12-day-old seedlings shallowly at regular wide spacing (ca 25 × 25 cm) and keeping the soil moist but not wet. In addition to introductory and closing chapters, there are six papers on research findings on growing rice with reduced water applications at sites in China, India, Indonesia, Thailand and Madagascar, and 10 papers reporting experience and evaluations from nine countries in South and South-East Asia, the Middle East, tropical Africa and Central America. The country reports describe the economic benefits: growing rice in aerated soil uses less labour and bullock/tractor power for land preparation, and it enables roots to penetrate more deeply and use nutrients more efficiently; keeping soils moist instead of wet uses less water; and plants growing under SRI conditions are more efficient at capturing solar energy. The result is greater output with less input. Overall, yield increases over customary cultivation methods averaged over 60%, although varying between and within countries. Studies in India, Indonesia, Kenya and Mali reported production costs reduced by 20–32% and profitability per hectare increased by 52–183%. Especially needed now are adaptation of SRI techniques to different climatic, soil and cultural environments, and stronger institutional support.