The General Health (GHQ-12) Questionnaire has proven to be an effective tool for the evaluation of mental health in clinical patients and the general population, being one of the most validated screening instruments used in the world and one of the most recommended to be used in health surveys. The objective of this study was to evaluate the psychometric properties of GHQ-12, in a group of 85 patients admitted into a Hospital in the city of Medellin in order to identify the psychological comorbidity of their health problems. Once the semantics of the rating scale was adapted, a confirmatory factor analysis was performed using the method of principal components for two factors, and it was found that the factorial structure explains the 51.76 % of variance. For each factor, the items were grouped and named as “psychological well-being” and “psychological discomfort”; finally, the normative scores according to the GHQ scoring system were determined, which uses a binary system (0, 1) and showed an average score of 5.34, which suggests a cutoff higher than 5 as an indicator of perception of psychological discomfort. Based on the analysis it was found that although there is a structure of two factors, this structure can be explained as two parts of the same component (positive and negative). The analysis of internal consistency using the Cronbach alpha-coefficient, showed a good internal consistency and validity (.84). After evaluating its psychometric properties item 11 was discarded for showing an inadequate factor loading. It is recommended to change the current name of the instrument to “general health short questionnaire (GHQ-R, 2011) to be implemented as an instrument of primary evaluation in Mental Health for this population.