The present paper examines the adaptation of English loanwords in Bemba particularly substitution of vowels. According to Central Statistics Office of Zambia (2010), Bemba (coded by Guthrie (1948) as M42, is a widely used language of communication spoken by 33.5 percent of 13,092,666 people. It is a study of vowel substitution in Bemba which concludes that the recipient language reshapes English vowels to the closest available vowels in its phonemic inventory. The paper reveals that vowel substitution is a patterned and systematic phenomenon in Bemba loanword phonology. This research also concludes that, on the basis of available vowel substitution patterns, it is possible to make predictions regarding the upcoming English words where similar substitution of vowels may be observed.