The book “Salicylic acid: A Plant Hormone” was first published in 1997 and was praised for its excellent balance of traditional and modern topics. This time, we're building on the success of the prior edition to provide an even more effective second edition. The present book is comprised of 16 chapters highlighting the updated mechanisms of its biosynthesis, physiological role, its action in response to water deficit, relationship of SA with signal transduction, transport of SA and related compounds. Further, the interplay between environmental signals and SA, its impact on transport and distribution of sugars, salicylic acid mediated stress-induced flowering and some aspects of interplay of SA with JA during the establishment of plant resistance to pathogens with different types of nutrition and participation of peroxidases have also been discussed at length. Potential use of SA in food production and its efficiency on post-harvest of perishable crops as well as practical use of SA are also covered. ??