Stress radiographs were taken of 42 sound stifle joints, of five stifles with injuries other than cruciate disease, and of 72 stifles with surgically confirmed cranial cruciate damage. The stifles were also examined by the cranial drawer test. No false positive compression radiographs were obtained. In the 72 stifles with cranial cruciate damage, instability was diagnosed on the stressed view in all but two cases. The sensitivity of the radiographic tibial compression test was 97 per cent, compared with 86 per cent for the cranial drawer test; the specificities of the tests were 100 per cent and nearly 98 per cent, respectively.