Background and objectives: The DASH-II scale is a specific instrument for measuring psychopathological symptoms in people with severe and profound intellectual disability (ID). The aim of the study is the validation of the Spanish version, evaluating its reliability and validity. At the same time we examine the prevalence of mental disorders in our sample. Material and methods: Two reviewers independently passed the Spanish version of the DASH-II (DASH-II-S) to 83 users to establish inter-rater reliability. To assess inter-rater reliability or test-retest reliability, fifty participants were reassessed by the same rater within 7 days. Results: DASH-II-S showed good internal consistency (Cronbach's alpha = 0.879) and good reliability, both intra and inter-rater reliability. The prevalence of psychopathology in the sample is 94%, and the use of psychotropic drugs is also high, with 61.4% receiving one or more antipsychotics. Conclusions: DASH-II-S is a valid and reliable instrument that can be used for the assessment of psychopathology in people with ID. The translated version retains the psychometric properties of the original English version. Moreover, the high prevalence of mental disorders in this population may explain the widespread use of psychotropic drugs, but it forces us to continuous reassessment and justification. (C) 2014 Elsevier Ltd. All rights reserved.