This study ought to find out the influence of use of mother tongue on students’ performance in English in kamuganguzi sub county, Ndorwa West constituency kabale district. Literature from across the globe, regionally was reviewed to provide various perspectives regarding the use of mother tongue in school and its influence on performance in English. The literature reviewed highlights how first language affects second language. It discusses both content in favor of use of mother tongue and content against the use of mother tongue among other issues. In this study, the target populations were students and English teachers from Kamuganguzi sub county secondary schools in Kabale. Two Schools were sampled using simple random sampling while 108 students were sampled using stratified sampling and systematic random sampling respectively. Four Teachers were sampled using purposive sampling technique. Questionnaires were used to collect data from students and teachers, while an interview guide was used to collect data from the teachers. The study found out that use of mother tongue had a negative influence in performance of English in secondary schools of kamuganguzi sub county. It emerged from the study that use of mother tongue influences the way students write and pronounce in English, hence negatively influencing the performance of English. Among other recommendations, the study recommended that teachers should come up with teaching methods that are interactive in the English curriculum so as to ensure that students are given an opportunity to interact with each other in English. Finally, the study suggests that this research should be replicated in other districts where students do not perform well in English to corroborate findings on how mother tongue influences performance of English.