To evaluate the criterion validity of the Birmingham Bowel and Urinary Symptoms Questionnaire (BBUSQ-22). Forty-four women presenting with urinary or bowel symptoms to a urogynaecology/functional bowel clinic, completed three disease-specific questionnaires (Birmingham Bowel and Urinary Symptoms Questionnaire, Sheffield Prolapse Symptoms Questionnaire and King's Health Questionnaire) and two generic questionnaires (SF-36 and EuroQol). Wilcoxon rank sum tests, Spearman's rank correlations and multiple regression analyses were undertaken. All clinically hypothesised correlations between the questionnaires' domains were found significant, and all domains hypothesised to be predictors of the BBUSQ-22 domains were proven to be prognostic, without explaining too much variability to doubt their uniqueness. The similarity among the measures has been proved without such relationships being too strong to call into question the distinctiveness of the concepts being measured. Overall, criterion validity is demonstrated, and the clinical usefulness of the addition this questionnaire makes to the area is highlighted.