Abstract Extensor tenosynovitis of the wrist can lead to rupture of the extensor tendons. Extensor tenosynovectomy is indicated if the tenosynovitis cannot be controlled by conservative measures. Open tenosynovectomy requires extensive dissection of soft tissue, including the extensor retinaculum. This article describes extensor tendoscopy of the wrist. This technique allows approach to the extensor compartments with small incisions and minimal soft tissue dissection. It is indicated when extensor tenosynovitis persists despite adequate medical treatments including medications, immobilization, and steroid injection. Synovectomy of the extensor compartments can be performed with preservation of the extensor retinaculum. This technique is contraindicated if the wrist cannot be flexed or there is severe tendinopathy of the extensor tendon that may need open reconstruction. The purpose of this technical note was to describe a minimally invasive approach of complete synovectomy of the extensor compartments with preservation of the extensor compartment. Technique Video video See video under supplementary data.