Gemination is a phonetic phenomenon whereby two identical /sounds/ co-occur in one word or at words boundaries. The co-occurrence of two identical sounds doesn’t matter, what matters is their pronunciation. Whether to pronounce them as one sound or two sounds is a matter treated differently across languages that have geminate sounds. As the present paper restricts itself to two languages only, Arabic and English, it investigates how gemination occurs in the two languages and how it can be represented? Is it restricted to consonants only or it can also occur with vowels? What type of gemination each language exhibits? These questions beside some more others are the main concern of the present paper in which the phenomenon of gemination is clarified in general, then a study of gemination is presented in English and Arabic respectively. There is a common view point which holds that English does not have gemination, but in fact it appears that English has gemination at certain conditions. Although it is unlike Arabic in its realization, but it can be said that gemination exists in English.