Cases of disruptive behavior problems such as inattentiveness, bullying, violence, drug abuse, hitting other pupils, teasing others, yelling and complaining amongst pupils in public primary schools in Mathioya Sub-county are on the rise. The purpose of this study was to evaluate the relationship between peer counseling activities and pupils’ discipline in public primary schools. A sample size of 196 respondents were selected. The study established that there was significant relationship between peer counseling activities and pupils’ discipline at the p<0.05[r = 0.001, p = 0.001]. This indicates that, in public primary schools where teachers frequently engage in peer counseling activities, pupils manifest few cases of indiscipline. The implications of this finding are discussed.