The translation of existing healthcare measurement scales is considered a feasible, efficient and popular approach to produce internationally comparable measures. The short form of the McGill Pain Questionnaire is one of the most widely used and translated instruments to measure the pain experience. The Greek version of the short form of the McGill Pain Questionnaire (GR-SFMPQ) has recently been developed and demonstrated satisfactory levels of internal consistency. The objective of the present study was to assess the instrument';s reliability and sensitivity. Eighty patients with spinal or knee pain were included. The test–retest reliability of the instrument was estim-ated for measurements within the same day and after 15 days. The sensitivity of the measure was examined before and after the application of a physiotherapy therapeutic regime. The correlation coefficients (Intraclass Correlation Coefficient and Spearman';s) ranged from 0.87–0.98 for within-day measurements and from 0.70–0.92 for administrations between days. All indexes of the GR-SFMPQ (total score, sensory and affective scores, total count of used words, visual analogue score, present pain index) managed consistently to detect the changes in pain experienced (p<0.05), after a therapeutic intervention, when assessing for the sensitivity of the questionnaire. An explorative discriminant analysis of the GR-SFMPQ indexes managed to correctly classify up to 85% of the patients; a classification rate comparable to the full version MPQ rating capacity. It can be argued from the results of this study that the Greek version of the SFMPQ fulfils the criteria of reliability and sensitivity to fluctuations of pain and can be utilized with confidence in cross-cultural comparative research trials.