Prof. P. Narayanasamy was awarded the B.Sc.(Ag.) (1958), M.Sc.(Ag.) (1960), and Ph.D. (1963) degrees by the University of Madras and later the Rockefeller Foundation Fellowship to pursue Postdoctoral research on Rice Virus diseases at the International Rice Research Institute, Philippines during 1966 - 1967. He served as the Virus Pathologist at the Indian Agricultural Research Institute, New Delhi during 1969 - 1970. He returned to his Alma Mater which was upgraded as the Tamil Nadu Agricultural University (TNAU), Coimbatore in 1971. He was appointed as the Associate Professor and promoted later as the Professor and Head of the Department of Plant Pathology. He was elected as the Fellow of Indian Phytopathological Society, New Delhi. He functioned as the Editor of the Madras Agricultural Journal published from the Tamil Nadu Agricultural University Campus and as member of editorial committees of the Plant Pathology Journals published in India. He was invited to participate as the lead speaker and chairman of sessions in the National Seminars held in India. As a researcher in Plant Pathology, he was the leader of the projects on diseases of rice, legumes and oilseeds. He organized the National Seminar for the Management of Diseases of Oilseed Crops. His research on antiviral principles yielded practical solutions for the management of virus diseases affecting various crops. He published over 200 research papers in national and international journals. He was the Principal Investigator of several research projects funded by the Department of Science and Technology, Government of India, New Delhi and the International Crops Research Institute for Semi-Arid Tropics, Hyderabad, India. He continues to share his experience and knowledge with the staff and graduate students of the Department of Plant Pathology, TNAU, Coimbatore. As a teacher, he taught courses on Plant Virology, Molecular Biology, Physiopathology, and Crop disease management for Master and Doctoral programs. Under his guidance, graduate students (25) and research scholars (15) earned Master and Doctoral Degrees respectively. With long experience and in-depth knowledge on various aspects of microbial plant pathogens and crop disease management, he has authored 18 books published by leading publishers like Marcel Dekker, John Wiley, Science Publishers, The Haworth Press, and Springer Science. These publications cover various aspects of Plant Pathology and serve as source of information and well received by the intended audience. As the social obligation, he is deeply involved in the social welfare activities to help the orphaned old and infirm people, as well as children through Udavum Karangal (Coimbatore), HelpAge (New Delhi), Global Cancer Concern (New Delhi), CRY (Bangalore), and The Hindu Mission Hospital (Chennai) to lessen the sufferings of needy persons. As one interested in literature and spirituality, he has composed poems in Tamil and English and published two collections of poems to inculcate self confidence in the youth and spiritual exploration for the mature people.