Inventions are the agents of change and have been the driving force behind the paradigm shifts that occurred throughout human history. There have been several paradigm shifts in the field of weed science too. The first one was the birth of modern weed science seven decades ago in 1944 when 2,4-D became commercially available. Since then, hundreds of newer organic herbicides have been developed and these became the mainstay of weed management in cropping and non-cropping systems around the world. The second paradigm shift was the evolution of herbicide resistance in 1968 when Senicio vulgaris was found resistant to 2,4-D. This was followed with hundreds of reports till today.  The  third paradigm shift in weed science occurred in 1994 when transgenic herbicide resistance crops, beginning with the approval of bromoxynil-resistant BXN cotton developed by Calgene and Rhône-Poulenc and glyphosate resistant soyabean developed by Monsanto, both in USA. These paradigm shifts has led challenges to India and Indian weed scientists too. This paper presents the various research challenges  required to be worked, both directly and indirectly by the Indian scientists.