This book has been written mainly for the students of BSc (Hons.) Agriculture and Horticulture) students as per the syllabus recommended by the Vth Deans committee. Apart from basic theory and constructional features a number of solved and unsolved problems have been included. The efforts have been taken to make it simpler and thorough for the understanding of the students. The topics covered in the book will enable the students to understand the basic principles, components, construction and working of an engine and different farm machinery. The book is fully illustrated with drawings and photographs depicting working components and operational features of the engine and farm machinery.