Sixty-two patients (sixty-eight shoulders) who had been treated non-operatively for idiopathic frozen shoulder were evaluated subjectively and objectively at two years and two months to eleven years and nine months of follow-up (average, seven years). Thirty-one (50 per cent) of these patients still had either mild pain or stiffness of the shoulder, or both. The range of motion averaged 161 degrees of forward flexion, 157 degrees of forward elevation, 149 degrees of abduction, 65 degrees of external rotation, and internal rotation to the level of the fifth thoracic spinous process. Thirty-seven (60 per cent) of the sixty-two patients still demonstrated some restriction of motion as compared with study-generated control values (calculated as the average motion, in each plane, for the thirty-seven unaffected shoulders of the patients who had unilateral disease). Ten patients had restriction of forward flexion; eight, of forward elevation; seventeen, of abduction; twenty-nine, of external rotation; and ten, of internal rotation. However, when the motion of each affected shoulder of thirty-seven patients who had unilateral involvement was compared with that of the unaffected contralateral shoulder, eleven (30 per cent) demonstrated some restriction. None of these patients had restriction of forward flexion; two had restriction of forward elevation; two, of abduction; seven, of external rotation; and seven, of internal rotation. The patients who had substantial restriction in three planes or more were thirteen times more likely to be men (p greater than 0.05). Marked restriction, when it was present, was most commonly in external rotation. Only seven patients (11 per cent) reported mild functional limitation.(ABSTRACT TRUNCATED AT 250 WORDS)