Many children consider getting a needle to be one of their most feared and painful experiences. Differentiating between a child's experience of fear and pain is critical to appropriate intervention. There is no gold standard one-item self-report measure of fear for use with children. Objective: To conduct an initial investigation of the psychometric properties of the Children's Fear Scale (CFS; based on the adult Faces Anxiety Scale) with young school-age children. Method: Children and their parents were filmed during venipuncture and completed pain and fear ratings immediately after the procedure (n = 100) and 2 weeks later (n = 48). Behavioral coding of the procedures was conducted. Results: Support was found for interrater reliability (Time 1: rs = .51, p < .001) and test–retest reliability (rs = .76, p < .001) of the CFS for measuring children's fear during venipuncture. Assessment of construct validity revealed high concurrent convergent validity with another self-report measure of fear (Time 1: rs = .73, p < .001) and moderate discriminant validity (e.g., Time 1: rs = −.30, p < .005 with child coping behavior; rs = .41, p < .001 with child distress behavior). Conclusions: The CFS holds promise for measuring pain-related fear in children. In addition to further investigation into the psychometric properties of the CFS during acute pain with a wider age range, future research could validate this measure in other contexts. The utility of a one-item measure of fear extends beyond the field of pediatric pain to other contexts including intervention for anxiety disorders and children in hospital.