This book is second in series of Essentials of Biostatistics wherein the first book provided the overview of Biostatistics concepts and methods with the help of R software. The current book will focus on the use of SAS software as most of the users in the biomedical field uses SAS because of its recognition especially the United States government agencies like Food and Drug Administration (FDA). The important note is that the book will not repeat the biostatistics concepts and methodology explained in the first book and it will concentrate mainly on the SAS software part and it is strongly advisable to use both books to get a complete idea of biostatistical concepts and methodology especially for the beginners.