ICRP Publication 78 replaces the previous ICRP Publication 54 on individual monitoring programmes and the interpretation of results of measurements for intakes of radionuclides by workers. The updating was considered necessary because ICRP published new dose coefficients for intakes of radionuclides by workers in 1994 (ICRP Publication 68). Those new dose coefficients were based on the most recent general recommendations of the Commission (ICRP Publication 60). The present report uses this new information and takes account of the new principles for the radiological protection of workers provided in ICRP Publication 75. Thus, the report uses the revised models and the new dose coefficients to give guidance on monitoring programmes and interpretation of results for selected radionuclides of importance in occupational exposure.