Juvenile delinquency has been on the increase and is being reported in different parts of the world including Nigeria (Oloruntimehin, 1992; Krug et al., 2012). Even though studies have associated psychiatric disorders with crime and delinquency (Wasserman et al., 2002; Loeber et al., 2001; Lynam, 1996), many of the mental health needs of such incarcerated juveniles go unrecognised (Kroll et al., 2002; Chitsabesan et al., 2006), this has become an important challenge facing the juvenile justice system (Cocozza and Skowyra, 2000). Only few of such studies have been reported in Nigeria, most of which were conducted in the southern part of the country. The Computerised Diagnostic Interview Schedule for Children (C-DISC 4.0) (Shaffer et al., 2000), the Antisocial Tendency Scale of the Carlson Psychological Survey (Carlson, 1982) and the Oslo 3-item Social Support Scale (Dalgard, 1995) were used to collect data on the prevalence of psychiatric disorders, level of social support and the measure of delinquency from 70 respondents at the Borstal Training Institute Kaduna. Their ages ranged from 14 – 17 years with a mean of 16.43 years and a standard deviation (SD) of ±0.83. Forty (57.14%) of the respondents were Christians while 30 (42.86%) were Muslims. Even though Hausa was the single largest ethnic group (35.72%), several other ethnic groups were represented; these include Igbo (17.14%), Yoruba (2.86%) and others (44.28%). Most of the respondents did not complete one level of education or the other; 4.29% did not complete primary school education, 35.72% did not complete junior secondary school education while 48.57% are yet to complete senior secondary school education. The prevalence of psychiatric disorders (including Conduct and Substance Use Disorders) was 95.7%. When Conduct Disorder was eliminated, 74.3% still met diagnostic criteria for at least one psychiatric disorder or another. Excluding Conduct and Substance Use Disorders, 41.4% still met criteria for one or more psychiatric disorder. The prevalence of other disorders were: Major Depression (15.7%), Nocturnal Enuresis (17.1%), Schizophrenia (7.1%), Social Phobia (5.7%), Separation Anxiety Disorder (5.7%), Specific Phobia (5.7%), Generalised Anxiety Disorder (1.4%) and Transient Tic Disorder (1.4%). There was a high rate of co-morbidity. Eighty four percent of the respondents met criteria for two or more co-morbid psychiatric disorders. When Conduct and Substance Use Disorders were excluded, 12.9% still met diagnostic criteria for two or more psychiatric disorders. Sixty one (87.1%) met the diagnostic criteria for Conduct Disorder while 36 (51.4%) of the respondents had one or more Substance Use Disorder. Most of those who had Substance Use Disorders 47.1% (33) were dependent on two or more psychoactive substances. The pattern of Substance Dependence seen was: Cannabis (38.6%), Nicotine (37.1%), Rohypnol (24.3%), Codeine (24.3%) and Alcohol (18.6%). Others include: Tramal (10%), Valium and Mogadon (10%), Solvent/Glue (2.9%), Cocaine (2.9%) and Benzhexol Abuse (10%). In this study, 36 (51.4%) had poor social support while 38 (54.3%) of the respondents had high Antisocial Tendency Scale score. There was a statistically significant association between Major Depression and Nocturnal Enuresis (P = 0.02). Nicotine Dependence was associated with Cannabis Dependence (P < 0.01) and also Alcohol Dependence (P < 0.01). Cannabis Dependence was significantly associated with Alcohol Dependence (P < 0.01). Other significant associations were: Rohypnol Dependence associated with Valium and Mogadon Dependence (P = 0.01); Rohypnol Dependence associated with Codeine Dependence (P < 0.01), Tramal Dependence and Benzhexol Abuse (P = 0.02). The respondents in the older age group (16 – 17 years) were significantly more likely to have Substance Use Disorders than those in the younger age group (14 – 15 years) (P = 0.02). Their mean Antisocial Tendency Scale score (M = 44.75, SD = 10.29) were also significantly higher than those of the 14 – 15 years old (M = 35.82, SD = 9.16) respondents (P = 0.01). High Antisocial Tendency Scale score was significantly associated with Conduct Disorder (P = 0.01), Alcohol Dependence ((P = 0.01) and Tramal Dependence ((P = 0.01). Poor social support had a significant association with Conduct Disorder (P = 0.01) and also with Alcohol Dependence (P = 0.042). There was also a significant association between poor social support and high Antisocial Tendency scale scores (P < 0.01). There was a very high prevalence of psychiatric disorders among the respondents along with a high rate of co-morbidity, multiple psychoactive substance dependence and poor social support. Delinquency was associated with Conduct Disorder and Substance Use Disorders. Recommendations were made on how to integrate mental health care services including a comprehensive drug rehabilitation programme into the correctional facility