The editors entitle the preface of their book “An Exciting Era in Polar Microbiology”. This is a fair statement because of the amount of information available, and the development of techniques. In addition recent concerted efforts to co-ordinate polar research have all reached a stage where the synthesis of the subject can be attempted with the aim of developing understanding from a whole book that is greater than the sum of the individual parts. This book takes a large step in this direction. This is a well presented book the origins of which are in the 2008 International Polar and Alpine Microbiology conference held in Banff, Canada. It is not, however, a conference proceedings. The individual chapters have been commissioned to provide an overview of the subject and draw together research from the International Polar Year in 2008. The book has 39 contributors with a strong North American presence. The book is divided into four sections: I. Microbial Diversity in Polar Environments, II. Adaptations and Physiology of Cold-Adapted Microorganisms in Polar Environments, III. Ecology and Biogeochemical Cycling of Polar Microbiology Communities, IV. Challenges to Living in Polar and Subpolar Environments, and comprises 14 separate chapters. The transition from consideration of the diversity of different groups, to adaptations and physiology, to ecology and then to future challenges offers a logical and structured approach to the subject which works well, presumably because the individual authors properly understood their mission and the editors worked hard to ensure good consistency and continuity between the chapters. In addition to leading the reader through the subjects, the individual chapters can stand alone, which is a useful attribute. Polar microbiology is an emerging set of disciplines potentially covering both the aquatic and terrestrial ecosystems which offer habitats where biological activity and processes are governed by extremes of water activity, and which also spans the extremes of latitude and altitude. Therefore polar microbiology spans a full range of taxonomic and physiological diversity. This books covers the topics well, although there are inevitably some gaps - for my part, I would have welcomed greater coverage of the protozoa and the algae, but this is a minor observation rather than a major criticism recognizing the fact that information and investigations on these groups are very sparse. The book is well-referenced, covering both the modern literature consistent with many of the authors being current researchers in their respective fields, and the older literature which is becoming increasingly difficult to access. The book is also strengthened by careful indexing. Of course, I have not checked every entry, but the samples I did check were accurate and helpful. This is to the credit of the editors because multi-author books often suffer from weak indexing, but not so in this book. So would I recommend it? I certainly think it has a place in institutional libraries and would be interesting to advanced level undergraduate and specialist postgraduate students and researchers.