Purpose. The aim of the study was to examine the relationships of early maladaptive schemas, overcompensation, and avoidant behaviors with sociodemographic, psychological, legal, and substance use status of individuals under probation due to illicit substance use. Methods. The data of this cross-sectional study were collected from adults under probation through self-report. The dependent variables were early maladaptive schemas, overcompensation, and avoidant behaviors. Sociodemographic, legal, and psychological characteristics and characteristics related to illicit substance use were the independent variables of the study. Student-t test and ANOVA or Mann–Whitney-U and Kruskal–Wallis tests were used in bivariate analyses. Multiple linear regression analysis was used in multivariate analyses. Results. A total of 300 adult individuals under probation participated in the study, and the inclusion rate was 93.5%. The mean age of the study group was 27.96 ± 6.40 years. The amount of smoking (B = 0.65 (95% CI: 0.04–1.27), p=0.038), frequency of illicit substance use (B = 12.15 (95% CI: 2.04–22.25), p=0.019), and childhood violence (B = 29.24 (95% CI: 16.92–41.56), p<0.001) were explanatory for schema scores (R2: 0.240). Frequency of illicit substance use (B = 7.06 (95% CI: 0.58–13.54), p=0.033) and childhood violence (B = 9.18 (95% CI: 1.36–17.00), p=0.022) were explanatory for compensation scores (R2: 0.083). The amount of smoking (B = 0.49 (95% CI: 0.22–0.76), p=0.001), frequency of illicit substance use (B = 5.16 (95% CI: 0.67–9.65), p=0.025), being treated for substance use disorder (B = 6.74 (95% CI: 0.30–13.17), p=0.040), and experiencing violence in childhood (B = 6.02 (95% CI: 0.59–11.45), p=0.030) were explanatory for avoidant scores (R2:0.169). Conclusion. Childhood violence and frequency of illicit substance use were associated with early maladaptive schemas, overcompensation, and avoidance. Smoking appears to be a behavioral way of coping with both early maladaptive schemas and schemas through avoidance.