The aim of this research was to study inter-rater and intra-rater reliability of lateral scapular slide test in three different positions; position 1: arm at side, position 2: hands on hip (45^o), position 3: 90^o shoulder abduction with medial rotation, using a calliper. 100 subjects, 50 with shoulder dysfunction and 50 without shoulder dysfunction, which included individuals of both genders, ranging in age from 19 to 65 years, participated in this study. Method: Two measurements of scapular distance, in each test position were obtained bilaterally. From the bilateral measurements, difference was derived. For interrater reliability, each rater obtained 1 reading of LSST in three positions on same day and for intrarater reliability, LSST was performed again after 48 hours again by the primary investigator (rater 1) in all three test positions. Intraclass correlation coefficients (ICCs) and the standard error of measurement (SEM) were calculated for intrarater and interrater reliability of the difference in side-to-side measures of scapular distance. Results: The ICCs for interrater reliability were 0.658,0.711, and 0.584 and 0.764, 0.506, and 0.567, respectively, for subjects without and with shoulder dysfunction in all 3 test positions. The ICCs for intra-rater reliability were 0.944, 0.783 and 0.890 and 0.484, 0.556 and 0.573 respectively, for subjects without and with shoulder dysfunction in all 3 test positions. Conclusion: Measurements of scapula position based on the difference in side-to-side scapular distance measures are not very reliable.