We have written this book as an introduction to fluid mechanics for students of all engineering disciplines. It may also be used by senior undergraduate and postgraduate students of physics and mathematics. The book is an outcome of teaching a third-year core-curriculum course at Kanpur for the past several years. The subject matter, with the exception of a few sections, can be covered in one 4-month semester, requiring about 40 lecture hours, 30 tutorial hours and 100 hours of home study. The prerequisites for such a course are: vector algebra and calculus, differential equation, particle and rigid body dynamics, and thermodynamics.