The majority of the existing Secondary Standard Dosimetry Laboratories (SSDLs) were established primarily to work with X rays and gamma rays. Neutron sources are, however, increasingly being applied in industrial processes, research, nuclear power development, and radiation biology and medicine. This publication deals primarily with methods of applying radioactive neutron sources for calibration of instrumentation and gives an indication of the space, manpower and facilities needed to fulfil the minimum requirements of a calibration laboratory for neutron work. Its intention is to serve as a guide for centres about to start on neutron dosimetry standardization and calibration. Contents: 1. Introduction; 2. Concepts of dosimetry and calibration; 3. Types of calibration and test measurement; 4. Sources, equipment and facilities; 5. Procedures and methods; 6. Calibration of beam dosimeters; 7. Reports and records; Appendix I: Basic quantities and units; Appendix II: Glossary; Apendix III: Neutron sources; Appendix IV: Fluence to dose equivalent conversion functions; Appendix V: List of symbols; References.