This textbook makes learning the basic principles of econometrics easy for undergraduate and postgraduate students of economics. It specifically caters to the syllabus of ‘Introductory Econometrics’ course taught in the third year of the Bachelor of Economics programme in many universities. Principles of Econometrics takes the readers step-by-step from introduction to understanding, first introducing the basic statistical tools like concepts of probability, statistical distributions and hypothesis tests, and then going on to explain the two variable linear regression models along with certain additional tools such as the use of dummy variables and various data transformations. The most innovative feature of this textbook is that it familiarizes students with the role of R, which is a flexible and popular programming language. Using R, students will be able to implement a linear regression model and deal with the associated problems with substantial confidence.