This text examines law and science. Law has always sought the assistance of scientists. If there is an upsurge in environmental and medical litigation - though changes to the legal aid system may frustrate this - there will be many opportunities to test the value of scientific testimony in court. It covers topics such as: the use of science in law; the lack of awareness of the way scientific knowledge develops; the ways to improve the scientific information available to courts; what thought needs to be given to techniques and processes, the ways such evidence is tested and admitted and to its probative value.