Unintended pregnancy and sexually transmitted infections among young people are priority public health issues globally. The UK and many other countries have adopted social marketing as the best approach to intervention despite limited evidence on efficacy. This book presents three studies carried out to address this gap. The first study is a systematic review assessing the effectiveness of social marketing in reducing unintended teenage pregnancies. The second and third are consumer research applications examining factors associated with contraception use and chlamydia screening. Results from the systematic review indicate that social marketing could be an effective approach in reducing unintended teenage pregnancies but evidence is limited to particular outcomes and context. The consumer research application studies show that it is an effective approach in generating vital intelligence about target populations, a prerequisite for designing effective interventions. Findings from the three studies provide much needed insight and should be of interest to public health professionals as well as anyone interested in understanding social marketing as applied to public health practice.Dr Anthony Simiyu Wakhisi is a public health expert and a Fellow of the Royal Society for Public Health (FRSPH).He has extensive experience working with public health teams within the UK National Health Service and Local Government.Prior to relocating to the UK he was a Country Health Programme Manager for Compassion International in Kenya.