OBJECTIVES: Develop a cross-cultural adaptation, English to Spanish, of the Clinically Useful Depression Outcome Scale (CUDOS): a validated instrument to assess depressive symptoms in patients with major depressive disorder (MDD). METHODS: CUDOS is a brief self-administered scale with 18 items assessing all of the DSM-IV inclusion criteria for MDD, psychosocial impairment and patients’ quality of life. Three independent translators (2 Spanish and 1 English) performed forward-backward translations of the original scale.  Draft version was reviewed by an expert panel (4 general practitioners, 1 psychiatrist, and 2 psychologists) and tested in 19 adult patients with MDD. Regarding experts’ and patients’ responses, comprehension and importance (C/I) of each item were evaluated using a Likert scale ranging from 0 (lowest level of C/I) to 4 (highest level of C/I). Furthermore, feasibility, ceiling and floor effects and reliability were preliminary analyzed. RESULTS: According to experts’ criteria, mean C/I values of items were over 2 points (comprehension mean range: 3.25-4 & importance mean range: 2.5-4). Regarding patients’ responses, acceptable mean values in comprehension (range: 2.26-3.37) were obtained. However, 4 items were modified to improve comprehension: loss of interest in usual activities, psychomotor retardation, indecisiveness and hopelessness Patients reported low importance scores in items related to thoughts of death (mean= 1.42), suicidal ideation (mean= 1.26), guilt (mean= 1.79), hypersomnia (mean= 1.37) and insomnia (mean= 1.78). Missing data was only found in 2 patients. Internal consistency was high (Cronbach α = .886), Neither item ceiling nor floor effects were observed and patients perceiving a moderate to severe psychosocial impairment obtained higher CUDOS scores –indicating a higher impact- than those with mild or null impairment (Mann-Whitney U=9.500; p=.019). Finally, the Spanish version of the CUDOS was reached by consensus. CONCLUSIONS: The original CUDOS instrument was culturally adapted into Spanish. Psychometric analyses are needed to validate this measure in Spain.