Background Suicidal behaviour remains challenging for clinicians to predict, with few established risk factors and warning signs among psychiatric patients. Aim We aimed to describe characteristics and identify risk factors for suicide attempts among patients with psychiatric disorders. Methods Multivariable logistic regression analysis, adjusted for clinically important confounders, was employed to determine risk factors for suicide attempts within a psychiatric patient population. Results The case (n = 146) and control groups (n = 104) did not differ significantly with regards to sociodemographic characteristics. The majority of the participants who had attempted suicide did so with high intent to die, and expected to die without medical intervention. The primary method of attempt was pharmaceutical overdose among the case participants (73.3%). Results showed impulsivity (odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.03?1.30) and borderline personality symptoms (OR = 1.07, 95% CI = 1.01?1.13) were significantly associated with attempted suicide. Conclusions Our findings indicate that known sociodemographic risk factors for suicide may not apply within psychiatric populations. Prevention strategies for suicidal behaviour in psychiatric patients may be effective, including limited access to means for suicide attempts (i.e. excess pharmaceutical drugs) and target screening for high-risk personality and impulsivity traits.