Visual analogue scales (VAS) are in widespread use for the measurement of pain, but there is little evidence as to their reproducibility. We have studied the longer-term reproducibility of four 10 cm scales in patients presenting with pain around the shoulder with a median duration of 18 months. One hundred and forty-five patients were studied. The Bland and Altman coefficients for repeatability at a median of 16 days were 6.4, 6.0, 4.2, and 3.3 cm, respectively. We conclude that pain VAS vary in their reproducibility, and that reproducibility beyond short time periods cannot be assumed. Each application should be tested individually. summary