This casebook is designed for use in courses on epidemiology or occupational epidemiology. The chapters are based on actual studies and are written by the principal investigators. They are divided into four parts: cohort studies, case-control and proportionate mortality studies, cross-sectional studies, and surveillance and screening studies. A brief introduction to each part describes the study design, and a statistical appendix is included so thatstudents can easily find the tools needed to answer analytical questions in the text. Questions in each chapter deal with study design, data collection, analysis, and interpretation. Complete answers are provided at the end ofeach chapter. Data sets accompany many of the chapters, and most of the analytical questions can be answered with a pocket calculator.