Objective To determine the effectiveness of scapular proprioceptive neuromuscular facilitation (PNF) techniques in patients with subacromial impingement syndrome (SIS). Methods 36 patients were randomized and a 6-week exercise program was applied to both groups 2 days a week. PNF group also received rhythmic initiation and repeated stretch PNF techniques in 2 scapula diagonals. Pain and function were primary outcomes. Active range of motion (ROM), pain pressure threshold (PPT), active myofascial trigger points (MTrPs), scapular dyskinesis, anxiety and depression status were secondary outcomes. Results The improvement in function, internal rotation ROM, PPT, active MTrPs and patient satisfaction was significantly greater in PNF group than exercise group (p<0.05). Scapular dyskinesis improved only in PNF group (p<0.05). Significant improvement in pain, function, ROM, PPT, active MTrPs, anxiety and depression was found in both groups (p<0.05). Conclusions Both scapular PNF techniques and standard exercise program are effective in the treatment of SIS. However, scapular PNF techniques can be added to the exercise program to further improve function, ROM, PPT, active MTrPs, scapular dyskinesis, and patient satisfaction.