This book contains an amalgamation of the essentials of basic biochemistry along with the advanced knowledge in the frontiers of molecular biology. The first edition of the book was published in 1995, and is now running the 6th edition. The book is now accepted as a standard textbook in all the medical colleges in India and abroad. Total of more than 100,000 copies have already been sold. The book has been designed with 7 sections. Section A deals with chemical basis of life. Section B is devoted to general metabolism. Section C describes clinical and applied biochemistry. Section D develops the clinical nutrition. Section E elaborates molecular biology. Section F denotes hormones and homeostasis. Section G is for advanced biochemistry. The 6th edition contains about 1,100 figures, 230 tables and 200 boxes, altogether making the book very student-friendly. Much emphasis has been given on clinical aspect of biochemistry, and the book is written aiming the students who are going to become practicing physicians. For example, chapter 24 gives the metabolic alterations in Diabetes Mellitus and in pre-diabetic states. Chapter 25 shows the relationship of cholesterol and lipoproteins with myocardial infarction. Chapter 26 gives the routine and special investigations done to identify liver diseases. Chapter 27 contains the alterations of parameters during kidney disease. Chapter 29 identifies the alterations in acid base balance and the life threatening conditions leading to changes in blood pH. Chapters on clinical chemistry have been extensively updated and clinically relevant points were further added. Out of the total 600 pages, more than 200 pages are devoted to the Clinical Biochemistry and Nutrition. Another 75 pages are devoted to the advances in Molecular Biology. Page 265 gives the details of cardiac markers, the alterations in serum enzymes during myocardial infarction. This text will keep the reader updated with important advances in the field of clinical biochemistry in a comprehensive but readable format.