Shreeyantra Rahasya is a Hindi spiritual book authored by Dr. Radhakrishna Shrimali and published by Manoj Publications in India. The book explores the mystical and esoteric significance of the Shri Yantra, an ancient sacred geometrical symbol used in Hindu worship and meditation. It details yantra sadhana, worship methods, installation procedures, and tantric practices aimed at spiritual growth and prosperity. Through insights into mantra, yantra, and meditation, the book guides readers toward wealth, happiness, and inner fulfillment. Written in accessible Hindi, this work blends traditional Indian spiritual wisdom with practical ritual guidance for seekers and practitioners.