It gives me immense pleasure in bringing out the second edition of essentials of genetics. This book has been conceived and organized according to the competency based medical education and all the comprehensive required of the medical students are included in this edition. This book has been made to meet all the goals as per newly framed MCI competency based guidelines for undergraduates. This has been done keeping in mind the need to deliver basic concepts genetics. Efforts have been made to keep the language simple and readily understood. The subject has been made interesting by including many coloured illustrations so as to enhance and facilitate reader's understanding of the pertaining text. A conscious effort has been made to keep the text concise yet lucid. Chapters such a as dermatologyphics, prenatal diagnosis and important techniques in genetics have been dealt with so as to keep pace with recent advances. Pedigree charts of various kinds of Inheritance have been discussed addition of a new section of at the end of each Chapter will equip students to better negotiate frequently asked questions on genetics in entrance examinations.