The term 'segment' is usually used in phonology to refer to the smallest perceptible unit. The main objective of this study is toprovide a phonological analysis of some of the segmental features of American English and Upper-Egyptian Arabic. The segmental aspect includes features related to single phonemes, such as duration (vowel and consonant length), vowel harmony and phonemic features, as well as aspects of connected speech, such as assimilation, epenthesis, elision and metathesis. The study revealed that American English and Upper-Egyptian Arabic show a great deal of similarity in relation to assimilation and elision but show more discrepancy in relation to epenthesis and metathesis.