The paper focused on how Islam influences fertilities globally. Theoretically, Islam through its writing encourages large families. The paper main objective is to examine whether this perception has been practiced among the Muslims and Muslim Countries or not. The methodology opted is table research through reading literature about the topic. Through various literature, Islam as religion is growing so fast globally, with an estimate of having followers more than 1.6 billion. This statistics does not justify whether the growth is from a natural increase or newcomers to Islam or through migration. The Islam insist on polygamy and discourage family planning this practice platform the evidence of how Islam encourages high population, but in practice, although encouraged by the whole scripture that Quran, Muslim countries almost half of them had low population growth. There a gap existing between the tradition of Islam and people`s practice. As to say people do not adhere to Islamic teaching.

Keywords : Islam, Fertility, Famil, Palnning, Countries, Polygamyand Women.