This edited volume contains a selection of chapters that are an outgrowth of the - ropean Conference on Mathematical and Theoretical Biology (ECMTB05, Dresden, Germany, July 2005). The peer-reviewed contributions show that mathematical and computational approaches are absolutely essential to solving central problems in the life sciences, ranging from the organizational level of individual cells to the dynamics of whole populations. The contributions indicate that theoretical and mathematical biology is a diverse and interdisciplinary ?eld, ranging from experimental research linked to mathema- cal modelling to the development of more abstract mathematical frameworks in which observations about the real world can be interpreted and with which new hypotheses for testing can be generated. Today, much attention is also paid to the development of ef?cient algorithms for complex computations and visualization, notably in molecular biology and genetics. The ?eld of theoretical and mathematical biology and medicine has profound connections to many current problems of great relevance to society. The medical, industrial, and social interests in its development are in fact undisputable. Insights and predictions from mathematical modelling are used increasingly in de- sion support in medicine (e.g., immunology and spread of infectious diseases, cancer research, cardiovascular research, neurological research, optimization of medical tre- ments,imaging),environmentalandnaturemanagement,climateproblems,agriculture and management of natural resources. Fast developments in areas such as biotechn- ogy (e.g., genome projects, genetic modi?cation, tissue engineering) continue to add new focal points of activity to the ?eld. The contributions of this volume capture some of thesedevelopments.