Chronic insertional Achilles tendinitis is a combination of Achilles tendon degeneration with retrocalcaneal bursitis and a Haglund deformity or enthesophyte. This typically is managed via open débridement and bone resection. In patients with more degenerative conditions, flexor hallucis longus tendon transfer is performed. This video reviews an all-inside technique that involves the use of an endoscopic strayer procedure, percutaneous calcaneal osteoplasty, and arthroscopic flexor hallucis longus tendon transfer. This procedure is indicated for patients with chronic insertional Achilles tendinopathy, large painful enthesophytes/Haglund deformity, or an Achilles tendon avulsion from chronic degeneration. Because this procedure is minimally invasive, it is associated with decreased blood loss, minimal soft-tissue disruption, decreased Achilles tendon scaring, quick return to functional activity, and improved postoperative shoe wear. Rehabilitation after the procedure necessitates 2 weeks of non–weight bearing and 6 weeks in a flat boot, followed by 6 weeks of a night splint. Overall, the all-inside, five-portal, minimally invasive surgical technique in combination with low-flow arthroscopy allows for improved visualization and less soft-tissue disruption while maintaining vascularity to the Achilles tendon. This video outlines the surgical steps for an all-inside technique.