The Day Hospital (DH) provides an intensive, multidisciplinary, coordinated, group and customized care for patients admitted for treatment. The therapeutic approach improve their clinical situation, their quality of life and facilitate their reintegration into everyday life. Our objective is to evaluate overall clinical improvement and perceived quality of life of patients admitted in a general hospital DH (2010–2012). Clinical diagnosis (DSM-IV-R) grouped (NSUD, SUD and DUAL), clinical variables, baseline/ high clinical situation (CGI-S), global impression of improvement (CGI-I) and related quality of life perceived (EQ5) at baseline / high were recorded. Data were analyzed using SPSS v15. 174 patients were evaluated, 58% women, mean age 47 years and schooling medium-high (76%). The average stay (DT) was 35 days. Patients came from 47%: acute hospitalization, 51%: Mental Health Center (MSC) or outpatient and 4%: other units. The reasons for admission were detoxification (34.5%), stabilization (33.3%), consolidation of detoxification (15.5%), decompensation (9.2%) and re-structuring of treatment (7.5%). The overall clinical improvement of the whole sample at the end of stay assessed by the CGI-I was: 35% = “much better” 38% = “moderately better”, 5% = “slightly better”, 21% = “no change” and only 1% “worse” (p = 0.001). An overall clinical improvement and quality of life perceived was observed in the three groups of patients. While it remains to know the persistence of these parameters in the long term, the Day Hospital proved to be an important therapeutic resource for overall clinical improvement of patients towards their incorporation into daily life.