At present, the most commonly used transfer dosimeters for radiotherapy applications are TL dosimeters. They are being used for intercomparison between SSDLs (about 70) and the IAEA dosimetry laboratory. However, there are some undesirable characteristics of this dosimetry system. We have a study in progress at the IAEA to evaluate the alanine-ESR system as an alternative to TLDs. There are several desirable qualities which make alanine an attractive dosimeter. Preliminary data suggest that the alanine-ESR dosimetry system has the potential to replace TLDs for intercomparison amongst SSDLs in the therapy-level dose region. Copyright (C) 1996 Elsevier Science Ltd