As far as Islamic Shari`ah is concerned, there is nothing in the sources of Shari`ah to the effect that the norm or the basic ruling of marriage in Islam is polygamy or taking only one wife. The ruling of marriage in either forms depends on the circumstances surrounding that marriage. Polygamy may be obligatory for a certain person and may be haram (Arabic for: prohibited) for another.
The eminent Muslim scholar and renowned da`iyahSheikh `Abdel-Khaliq Hasan Ash-Shareef states, It is not Islamically correct to say that the basic ruling or norm of marriage in Islam is polygamy or sticking to having one wife. There is nothing in the sources of Shari`ah to the effect that any of the two is the norm or the basic ruling and the other is not that. Had the basic ruling been polygamy, Almighty Allah would have created women more than the double of men in all ages and places in order for each man to be able to marry two or more women. That is because Almighty Allah did not order His creation to do the impossible. Almighty Allah always commands people to do what is possible.
So, what some Muslims may believe with regard to this issue is wrong. Furthermore, Muslim scholars are of the opinion that marriage whether in the form of polygamy or having one wife is subject to all the five Shari`ah rulings: wajib (obligatory), mandub (commendable), mubah (permissible), makruh (reprehensible), or muharram (prohibited). The ruling differs based on the circumstances surrounding the case in question.