The research reported in this book focuses on the social functions of Hausa-English code switching and the factors motivating the occurrence of code switching during the social interaction of Hausa bilinguals studying at University Utara Malaysia. The objective of the study is to examine the specific functions of code switching and certain aspects that usually influence the manifestation of code switching within the speeches and conversation of Hausa-English bilinguals. The data for the survey were collected by the researcher using questionnaires distributed to 80 bilingual participants, who completed them over a period of three weeks in December 2013. The collected data were analyzed within the framework of Gumperz (1982) six conversational functions of code switching and Malik (1994) ten reasons and functions of code switching. The study found that the systematic ability to alternate between two or more languages is natural and subconscious behavior which entails social values and purposes.