Various scoring systems have been proposed to quantify the disability caused by knee ligament injuries and to evaluate the results of treatment. None of these systems has found worldwide acceptance, mainly because all scoring systems attribute numerical values to factors that are not quantifiable, and then the arbitrary scores are added together for parameters not comparable with each other. For these reasons a group of knee surgeons from Europe and America met in 1987 and founded the International Knee Documentation Committee (IKDC). A common terminology and an evaluation form was created. This form is the standard form for all publications on results of treatment of knee ligament injuries. It is a concise one-page form. It includes a documentation section, a qualification section and a evaluation section. For evaluation there are four problem areas (subjective assessment, symptoms, range of motion and ligament examination). These are supplemented with four additional areas that are only documented but not included in the evaluation (compartmental findings, donor site pathology, X-ray findings and functional tests). The form can be used pre- and post-operatively and at follow-up. It has been specified that in any publication the minimum follow-up time for short-term results should be 2 years, for medium-term results 5 years and for long-term results 10 years. The largest part of the sheet is the qualification section. It is called "qualification" section rather than "scoring" section because no scores are given. Each parameter is qualified as "normal", "nearly normal", "abnormal" or "severely abnormal". This qualification is less subjective and emotional than "very good", "good", "fair" and "poor".(ABSTRACT TRUNCATED AT 250 WORDS)