This book is the result of years of academic study, teaching and research on the complex subject of sexually transmitted infections (STIs). With the discovery of syphilis in ancient Egyptians mummies, sexually transmitted diseases are probably as nearly as old as history could account for the existence of the human race. The fact that sex is the medium of transmission of these infections makes it a difficult to discuss subject in many cultures where discussions on sexuality and sexual activity are sacrosanct. The social construct and interpretation of societal norms relating to sex and infections relating to the sexual act, makes it difficult to deal with even amongst the most educated. The advent of newer STIs like the Human Immuno-deficiency Virus (HIV) renewed the fueling of stigma and discrimination which make disclosure difficult and negatively affect the health-seeking behavior of persons who may be infected with or exposed to any STIs. This second edition has been necessitated by a number of factors. The most important factor has been the need for this book to be up to date keeping in mind revision of guidelines and recommendations from relevant health agencies particularly the World Health Organization (WHO). Thus some chapters have seen major changes, for example, the Chapter 11 on the Human immunodeficiency Virus (HIV) has undergone significant revision particularly in the area of the diagnosis and antiretroviral therapy protocols backed by strong scientific evidence. Chapter 4 and 6 on Gonorrhoea and syphilis respectively has additional details and recommendations on the treatment guidelines. Some chapters have also been improved by making the points clearer and providing some additional information (e.g. Chapters 3 and 9). There has also been some formatting to improve the flow of thought for some chapters. It is my hope that all these revisions have made this edition better.