Summary. Sacroiliac joint dysfunction is one of the proved causes of sacroiliac joint syndrome. We are talking about the restricted mobility of sacrum opposite to ilium the type of »reversible blockage of movement«. Main characteristics of dysfunc- tion are as follows: restricted »joint play«, referred pain, normal radiological finding, normal lab results and disappearance of clinical symptoms after deblocking of articular bodies. Pain from a blocked joint can be referred to lower back, buttocks, hip, groin, thigh, calf and lower part of abdomen. Dispersion of painful regions is a consequence of a complex and variable innerva- tion of articular capsule. Blocked position of articular bodies and protracted tension of articular capsule causes a stimulus of nociceptors by which a capsule is protected. Nociceptive activity is manifested with referred pains in innervational region of stimulated sensitive nerves. In the article, besides the clinical manifestations, there is described a diagnostics and manual therapy of dysfunction. Springing tests by means of which a passive mobility (»joint play«) is being tested, are most valuable in dysfunction diagnostics. Manual therapy (mobilization/manipulation) is indicated and efficacious with the patients suffering from dysfunction.