This study examined the psychometric properties and diagnostic accuracy of the Swedish translations of the Spence Children's Anxiety Scale, self- and parent report versions, in a sample of 104 adolescents presenting at two general psychiatric outpatient units. Results showed high informant agreement and good internal reliability and concurrent and discriminant validity for both versions and demonstrated that this scale can distinguish between adolescents with and without an anxiety disorder in a non-anxiety-specific clinical setting. The relative clinical utility of different cutoff scores was compared by looking at the extent to which dichotomized questionnaire results altered the pretest probability of the presence of a diagnosis as defined by the Schedule for Affective Disorders and Schizophrenia for School-Age Children. Optimized for screening and diagnostic purposes in Sweden, cutoff scores obtained in the current study outperformed a previously identified cutoff score derived from an Australian community sample. The Spence Children's Anxiety Scale is a useful clinical instrument for the assessment of anxiety in adolescents.