Neurocognitive and academic deficits are frequent among male offenders and the prevalence of these disorders is known to be higher than in the general population. Also psychiatric disorders and substance dependence are overrepresented among offenders. Neurocognitive and academic deficits, psychiatric disorders and substance dependence are all known to be risk factors for offending and a criminal career. Studies on recidivism have mainly focused on the associations between ADHD (Attention Deficit Hyperactivity Disorder), psychiatric disorders, and violent crime, but have ignored connections to various psychiatric disorders and neurocognitive deficits and academic difficulties. The aim of this thesis is to examine the neurocognitive and academic performance in a sample of sentenced male prisoners in Finland. The frequency of reading, spelling, and mathematical difficulties was also analyzed. I also examined how neurocognitive deficits and academic difficulties are associated with psychiatric diagnoses, especially with substance dependence. If a specific profile of neurocognitive, academic and psychiatric factors among offenders could be found that is related to recidivism and criminal career, this could be more effectively targeted by intervention procedures. In a health survey of Finnish prisoners, 72 sentenced male prisoners were examined in Turku prison using a neurocognitive test battery and psychiatric assessment including a standardized psychiatric interview (SCID-I, II). First, a range of neurocognitive deficits was common, especially in motor dexterity, visual construction, verbal comprehension, verbal and visual memory, and shifting attention. Furthermore, recidivist men had problems indicating impulsivity. Second, the comprehensive neurocognitive deficits and illiteracy problems seemed to go together among prisoners. The results showed a high number of reading and spelling difficulties. Fifteen percent of those with medium to severe problems in academic skills had marked difficulties in mathematics. Third, major mental disorders (Axis I diagnosis) and substance dependence were connected with neurocognitive and academic deficits. Moreover, first- time offenders had fewer neurocognitive deficits and Axis I disorders, less substance dependence and fewer personality disorders than those with several convictions. Fourth, the combination of neurocognitive deficits and substance dependence was connected to recidivism. According to the thesis, the Finnish male offender could be described using four groups with different characteristics of neurocognitive, academic and psychiatric factors. Preventing the development of substance dependence, together with rehabilitation of neurocognitive deficits, seems to be important for reducing recidivism. We suggest that both selection and preparation for participation in offender programs might be more effective if specific neurocognitive deficits are identified and efforts first made to ameliorate them.