Abstract: Mobile phones are getting cheaper and smarter; therefore, the usage of mobile phones by university students is becoming more popular than ever before. This study sought to determine the comparative effects of mobile phone texting and social interaction among students of Catholic University of Eastern Africa and Catholic University of Zambia. The study employed symbolic interaction theory that brings to light; that meaning is attributed to things that arise out of social interaction. Literature review is later presented on the key objectives of the study as well as a conceptual framework; linking the independent variables to the dependent variable in light of intervening variables. The study used the descriptive research design since it incorporates the use of questionnaires in collection of qualitative and quantitative data. The study target population was the students of The Catholic University of Eastern Africa and the students of The Catholic University of Zambia, totalling to 2,913 students. The study applied simple random sampling where a total of 385 students were selected. The response rate was 80% of the sample, presenting 309 students. The research finding was that students from The Catholic University of Zambia spend more time texting compared to students from Catholic University of Eastern Africa. The finding led to the recommendations that the time spent on texting should also be regulated by the students themselves by responding to only urgent text messages in class settings and among peers. The school should also initiate a policy where texting during class hours is only restricted to urgent cases. Conclusion of the study is that mobile texting affects social interaction of students. Key Words: social interaction, texting, mobile phone use, student, university