BackgroundMental disorders are associated with an increased prevalence of substance use disorders (SUDs). Despite this comorbidity being firmly established, alcohol and nicotine risky use and misuse are not routinely and systematically assessed in clinical practice. ObjectiveThe aim of this study is to examine the prevalence of risky use of alcohol, alcohol use disorder (AUD), smoking, and nicotine use disorder in people with psychiatric diagnoses and their association with age, gender, and occupational functioning. MethodParticipants were 210 patients from an inpatient psychiatric ward. Three self-reporting questionnaires were used: the Alcohol Use Disorders Identification Test (AUDIT), the Lübeck Alcoholism Screening Test (LAST), and the Fagerström Test for Nicotine Dependence (FTND). ResultsRisky alcohol use or AUD was found in more than one third of patients and was more common in males than in females (p<0.01) and in young people as compared to older adults (p=0.04). Current nicotine consumption concerned over a half participants and was significantly associated with risky alcohol use and AUD (p<0.01). Patients with current SUD had the highest prevalence of both smoking (80%) and alcohol misuse (80%). Low occupational functioning was associated with both alcohol use (p=0.02) and concurrent alcohol and SUDs (p=0.03). ConclusionsBoth alcohol and nicotine risky use and misuse are highly prevalent in people with psychiatric disorders and their concurrent abuse is common. The simultaneous use of different screening questionnaires allows the identification not only of people with frank use disorders, but also those with harmful use, facilitating early detection of people at risk.