The 1st edition of book entitled "Design of Machine Elements" for IIIrd Year Diploma, Semester VI in Diploma in Mechanical Engineering Group as per the syllabus prescribed by SBTE. We have observed the students facing extreme difficulties in understanding the basic principles and fundamental concepts without adequate solved problems along with the text. To meet this basic requirement of students, sincere efforts have been made to present the subject matter with frequent use of figures and lots of numerical examples.