Aim: The study has been aimed at comparing the group of patients diagnosed with conduct disorders hospitalised at the Department of Adolescent Psychiatry of the University Hospital in Krakow in the period of 1990–1991 with the corresponding group of patients hospitalised in the period of 2014–2015, in terms of the clinical picture, family status and the frequency and characteristics of their hospital stays. Material and method: The medical records of patients hospitalised in the period of 1990–1991 and 2014–2015 diagnosed with conduct disorders were used as the research material. The records were analysed in terms of the demographic and hospitalisation data, the patients’ care status, their exposure to abuse as well as selected symptoms related to conduct disorders in adolescents. Results: The obtained results have demonstrated the number of hospital admissions due to conduct disorders to have increased over three times over the period analysed. Also, the medical records covering the period of 2014–2015 showed a statistically significant greater number of patients with an unstable care status, greater prevalence of suicidal attempts and greater prevalence of self-harming behaviours compared to the medical records covering the period of 1990–1991. Conclusions: The observed increased frequency of hospital admissions of adolescents with conduct disorders may be associated with the increased prevalence of impulsive self-destructive behaviours such as self-harm and suicidal attempts in this population. The decline in care stability (despite the lack of clarity concerning the extent and the nature of this phenomenon in a wider population) and the associated decreased efficiency of the care system in the case of a crisis such as exacerbating impulsive self-destructive behaviour in adolescents create circumstances in which interventional psychiatric hospitalisation becomes inevitable. In light of the obtained results and the preliminary hypotheses regarding their causes, an additional question arises regarding the efficiency and availability of outpatient mental health care, auxiliary mental health services for patients from the studied population and their families, who should be considered the forefront of the possible and necessary therapeutic measures to be taken.