Background A quick method of assessing readiness to change was needed for a major study of implementing screening and alcohol brief intervention in England. For this purpose, a Readiness Ruler that had been validated among a sample of male college students in the USA was adapted and applied to a sample of excessive drinkers in a general medical practice located in a deprived area of Gateshead, England. Methods 72 participants identified as excessive drinkers by health professionals completed a single-item Readiness Ruler, the 12-item Readiness to Change Questionnaire (RCQ) and the AUDIT questionnaire. Results In terms of concurrent validity, the relationships between the Readiness Ruler, on the one hand, and either stage of change allocation or a dimensional score derived from the RCQ, on the other hand, were highly significant but weaker than expected. When patients who endorsed the “maintenance” point on the Readiness Ruler were excluded from the analysis, the above relationships were considerably strengthened for reasons that are discussed. On this basis and with another small change, a final Readiness Ruler was developed. Conclusion If the validity of the Readiness Ruler is confirmed in subsequent research, a quick and simple way of measuring readiness to change will be available for research or clinical work with alcohol brief interventions.