Fractures of the distal radius, which currently are treated with palmar locking plates, are often accompanied by carpal lesions. Tears of the scapholunate interosseus ligament (SL) can affect the outcome. Between January 2007 and May 2008, 28 patients with distal intraarticular fractures of the radius were included in a prospective study. Preoperative CT-arthrography was performed. SL tears were found in 11 patients, with 10 partial and one complete rupture observed. A tear of the triangular fibrocartilage complex (TFCC) was detected in 16 patients. Every patient was operated with a palmar locking plate through a palmar approach between the flexor carpi radialis tendon and the radial artery. Then, a palmar wrist arthroscopy using a palmar portal was performed. Eleven SL tears with 9 partial and two total ruptures were diagnosed by arthroscopy. Ten lesions were associated with a C1-fracture with a fracture line projected onto the scapholunate interval. The TFCC was appraisable by palmar wrist arthroscopy only in 4 patients. Three of the SL tears detected by CT-arthrography could not be confirmed by palmar wrist arthroscopy. One complete rupture and one partial lesion confirmed by palmar wrist arthroscopy were found by CT-arthrography to be intact. Palmar wrist arthroscopy affords certainty when assessing the SL ligament. In this study, an assessment of ulnocarpal structures was not possible. For assessment of the ulnocarpal structures, CT-arthrography was superior to palmar wrist arthroscopy. However, the latter is an alternative during emergency treatment or when CT-arthrography is not available.