Aim. The aim of the article was to draw attention to the problem of psychiatric complications of intensive chemo- and radiotherapy administered in childhood. At present most children suffering from acute leukaemia are successfully treated. However, intensive chemo- and radiotherapy are known to affect young patients' mental state.
Case report. A case is reported of a man in remission of leukaemia for the past 15 years. His current personal and social functioning is severely affected by his cognitive impairment and delusional syndrome.
Conclusions. At the time when acute lymphoblastic leukaemia can be successfully treated, new treatment regimens should be introduced taking into account delayed complications of chemo- and radiotherapy in childhood.