Behavioural problems among students are a challenge in most Kenyan schools and the occurrence of behavior problems among students has been reported in Kisii County. Since most of the previous studies have focused on external factors that influence indulgence in behavior problems among students and scanty information in literature on internal psychological states necessitated the present study. The purpose of this study was to establish the relationship between internal psychological states and indulgence in behaviour problems among secondary school students in Kisii County of Kenya . The study objectives were; To establish the relationship between personality subtypes, and student indulgence in behaviour problems, To determine the relationship between students' self-esteem and indulgence in behavior problems, to determine relationship between students self-efficacy and indulgence in behaviour problems and to find out the relationship between locus of control and student indulgence in behaviour problems. The study was informed by Eysencks theory of criminal personality, theory of planned behaviuor and Person centred theory. A Concurrent Triangulation Design within the Mixed Method approach was adopted. The target population was 11479 form three students drawn from three Sub Counties; Sameta, Kisii Central and Gucha South Sub Counties. A sample size of 386 students was involved in the study. The Eysenck Personality Questionnaire, Self-esteem scale, Self-Efficacy Scale, Locus of Control Scale and Indulgence in Behaviour Problem Questionnaire were used to collect quantitative data for the study. Interview schedule were used to collect qualitative data. Reliability of the instruments were determined using internal consistency and an index of 0.838 was reported. Validity of the instruments were ensured by expert judgement by University lectures. The study adopted stratified sampling technique for student respondents as simple random technique was used to draw participants for interview schedule. Quantitative data was analyzed by using inferential statistics, which included Analysis of Variance (ANOVA) and Pearson product moment correlation coefficient to test the hypotheses. Qualitative data was analyzed by using thematic analysis. The findings indicated that there was a statistically significant difference (at the p<0.05 level) in students' indulgence in behaviour problems scores for the three personality subtypes [F (2, 344) =1181.25, p<0.05]. That is, the indulgence to behaviour problems mean score for extroverted students was significantly different from the mean score of introverted students and neurotic. The mean indulgence in behaviour problem for inrrovert and neurotic students also differed significantly from each other. The study established a plausible negative (r = -0.564) correlation between students' self-esteem and indulgence in behaviour problems. The analysis revealed a highly significant (p< 0.05) negative relationship between the two variables, with high level of self-esteem associated with low level of indulgence in behaviour problems. The study shows that there was a strong negative (n=347, r = -0.612) but highly significant (p <0.05) correlation between students' self-efficacy and students' indulgence in behaviour problems with high level of self-efficacy associated with low level of indulgence in behaviour problems. The study also revealed that there was a statistically significant difference (p<0.05) in students' indulgence in behaviour scores for the three locus of control [F (2, 344) =40387.97, p<0.05] The teacher counselors should identify appropriate therapy techniques for the students at risk of indulgence in behavior problems.