The book is a collection of different researches carried-out in the department of Agricultural and Environmental Engineering of O.A.U. Ile-Ife and department of Agricultural and Bio-Environmental Engineering, Federal Polytechnic, Bauchi between 2012 and 2015. This book is specially produced to help any researcher seeking for some useful information about some post-harvest processing machines such as paddy rice thresher, Bambara-nut and neem decorticators. Engineering properties (physical, mechanical and aerodynamic) of neem seeds and kernels were provided in this book. This book is strongly recommended for young engineers and technologists in tertiary institutions.