Hallux valgus is the most common foot disorder associated with gastrocnemius tightness, and there is a particularly strong association with juvenile hallux valgus. This article describes an oblique windlass mechanism that can be a causative or a contributory factor in the pathogenesis of juvenile hallux valgus. This article presents a study of 108 patients who underwent a proximal gastrocnemius release and hallux valgus correction using a scarf osteotomy. We believe that assessment of gastrocnemius tightness in juvenile hallux valgus is important and that gastrocnemius lengthening should be routinely considered as part of the operative strategy.