BACKGROUND Arm slings are often used in clinical practice to support the hemiplegic arm aiming to prevent or treat glenohumeral subluxation. Evidence supporting the corrective effect of slings on subluxation is scarce and long-term studies are lacking. OBJECTIVE The aim of this study was to determine both the immediate and long-term effect on acromiohumeral distance using the Actimove® sling and Shoulderlift and to determine the effect of slings on pain and passive range of motion of the shoulder in stroke patients with glenohumeral subluxation. METHODS Randomized control trial. METHODS Hospital inpatients. METHODS Stroke patients. METHODS Twenty-eight stroke patients, with severe upper limb impairments, were randomly allocated to 3 groups (Actimove, Shoulderlift, No sling). Patients wore their supportive device for 6 weeks and no sling in the control group. Immediate and postinterventional effect on acromiohumeral distance was measured using sonography. Pain (VAS), ROM (goniometry), spasticity (Modified Ashworth Scale), Fugl-Meyer Assessment and trunk stability (TIS) were also assessed before and after the intervention. RESULTS The level of immediate correction of both slings was different at baseline and after 6 weeks (0 weeks: Shoulderlift 63%, Actimove 36%; 6 weeks: Shoulderlift 28%, Actimove 24%). Comparing the level of subluxation over time shows a distinct decrease in subluxation but only for the control group (-37.59% or 3.30 mm). Subluxation remained the same in the Actimove group (-2.77% or 0.27 mm) but increased in the Shoulderlift group (+12.44% or 1.03 mm). After 6 weeks, the Actimove group reported more pain at rest (P=0.036). ROM for abduction and external rotation decreased in 2 groups and remained un-altered in the Shoulderlift group. CONCLUSIONS Results of immediate correction varied. Subluxation seemed to reduce in patients that did not wear a sling. CONCLUSIONS The (assumed) presence of subluxation may not benefit from wearing an arm sling which may itself inhibit active correction. If a sling is indicated the Shoulderlift may be preferable to the Actimove sling.