In the face of the ever-increasing importance of statistical methods in medical research and practice, the first edition of this publication has provided a sound and deep understanding of statistical methods in bioassay to many students and researchers. In addition to the profound presentation of statistical methods of the first edition, here the reader will find new material stemming from the recent statistical literature as well as data reflecting modern trends in general applied statistical research. Examples are discussions on design and planning, e.g. choices of dose levels, an additional section in the chapter on Bayes methods, and a new chapter on sequential estimation for the logistic model. The book will be a valuable source of information to students in the experimental area of statistical aspects of biological assay, professional statisticians with an interest in research in this topic, teachers in statistics and biology, and investigators in the biological and medical sciences who use bioassay in their work.