Context Memorial Symptom Assessment Scale (MSAS) is a multidimensional tool developed to evaluate frequency, severity, and distress of common symptoms present in cancer patients. Objective To translate the original English version of MSAS and prove the reliability and validity of the Spanish version. Methods MSAS scale was translated into Spanish and administered to 246 cancer patients aged between 18 and 85 years. They attended the Day Hospital to receive chemotherapy. European Organization for Research and Treatment of Cancer Quality of Life Questionnaire–Core 30 and Rotterdam Symptom Checklist were used to test criterion validity. Results TOTAL MSAS, Physical Symptom Subscale (PHYS), Psychological Symptom Subscale (PSYCH), and Global Distress Index (GDI) reported high internal consistency: 0.891, 0.801, 0.825, 0.813, respectively. Exploratory factor analysis identified two-factors structure and confirmatory factor analysis showed good adjustment rates. The emotional functioning subscale of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire–Core 30 highly correlated with PSYCH (r = −0.868; P < 0.001) and GDI (r = −0.810; P < 0.001), whereas social functioning subscale correlated with PSYCH (r = −0.704; P < 0.001) and GDI (r = −0.624; P < 0.001). The PHYS of Rotterdam Symptom Checklist correlated with PHYS (r = 0.876; P < 0.001) and the PSYCH with PSYCH (r = 0.872; P < 0.001). Conclusion The Spanish version of MSAS was determined to be a valid and reliable scale in cancer patients.
