Communicable and non-communicable diseases account for most deaths in developing countries. Control of diseases is therefore one of the priorities for reducing high mortality seen in these countries. The book is written to assist those people who deal with communities in improving their health status and reducing disease transmission. Students of public health will find this book useful especially in modules that deal with disease control. It is written in very simple language and should be understood by all manner of professions and not necessarily those who have knowledge in health. The author has taught students of community health using the same notes and most of the students found the notes very useful. it is hoped that this book will enable students understand and apply basic principles in the control of communicable and non-communicable diseases within their communities.