Generally, the sacroiliac joint is not considered accessible for arthroscopy under physiological conditions. The non-injured joint is not large enough for introduction of even the smallest arthroscope into the joint space. After traumatic injury however, or in the event of an inflammatory condition or tumour formation, it is theoretically possible to position an endoscope in the joint space. Study of the anatomy of the sacroiliac joint and knowledge of the anatomic relations, particularly the vascular and nervous relations, is a prerequisite for arthroscopic exploration of the sacroiliac joint space. The posterior approach must account for the bone configuration of the iliac wing and the orientation of the sacroiliac joint line. A cadaver study confirmed the feasibility of endoscopic exploration of the sacroiliac joint via a posterior percutaneous access. Based on this anatomic experience, we positioned an arthroscope in an injured sacroiliac joint and report the different phases. A technique for obtaining a biopsy of the anterior aspect under endoscopic control has already been described, but to our knowledge, there is no arthroscopic description of the sacroiliac joint via a posterior access. Indications for arthroscopy of the sacroiliac joint remain very limited. This technique can be used to remove osteocartilaginous fragments or foreign bodies incarcerated in the joint and to obtain biopsy material, drain collections and, in the near future, should allow avivement of the cartilage surfaces with the objective of a percutaneous arthrodesis.