Scapular dyskinesis has been identified as a possible risk factor for injury in overhead athletes. There is a need to develop a simple, inexpensive, time efficient field based test that can establish the presence and severity of both scapular dyskinesis and the individual components of scapular dyskinesis in a musculoskeletal pre-participation screening. To ensure confidence in the test results, high reliability must be displayed. To establish the inter-tester and intra-tester reliability of a simple field based screening tool for scapular dyskinesis. Reliability study. Athletic therapy facilities. Patient or Other Participants: Fifteen physically active males (19.46±0.63years) free from any orthopaedic or neurological disorders were recruited from a convenience sample of collegiate students. Testers underwent three training sessions where the instructions and scoring system of the test were explained, demonstrations of the tests were given and opportunities to practice the test were provided. Three testers independently rated three trials and the process was repeated at the same time the following week. Scapular dyskinesis was assessed using the following components: winging, loss/lack of control when lifting, loss/lack of control when lowering and scapular asymmetry. A 0-3 rating (0=no issue, 1=slight issue, 2=moderate issue, 3=severe issue) was provided by the tester independently on each side separately and on scapular asymmetry. The intraclass correlation coefficients (ICC), 95% Confidence Intervals (CI) and standard error of measurement (SEM) statistics were computed to establish reliability. Excellent ICC values were found for inter-tester reliability (ICCs ranging from 0.80-1.00) and good to excellent intra-tester reliability (ICCs ranging from 0.60-1.00 for Tester A, 0.63-1.00 for tester B and 0.75-1.00 for Tester C) for all components of the test. The SEM was not found to be clinically significant. The simple field based screening tool developed to assess scapular dyskinesis demonstrates high reliability, and so is a reliable tool to utilise in a pre-participation screening. Future research should establish validity.