Four different behavioural tests, the holeboard, faecal counts, food preference, and operant behaviour were assessed for their ability to detect anxiolytic activity in the rat. In evaluating each of these tests, varying doses of a single anxiolytic and/or different types of anxiolytic compounds were given to the rats and the resulting behavioural changes recorded. Anxiolytics did not significantly alter behaviour on the holeboard, nor did they change food preference in accordance with expectations. At high doses anxiolytic did reduce faecal counts. While this may be a consequence of the anxiolytic activity of these drugs, their effect on gastric motilityper se was not assessed. During the extinction of an operant response (performed over a number of trials on successive days) anxiolytics consistently shortened the latency before the onset of pressing. It is suggested that this test may be of value in th edetection of anxiolytic activity in the rat.