This book presents the first national study of the practice of polygamy undertaken amongst Malay Muslims, contextualised within the broader social, legal, and political context of Malaysia. A collaboration between the Sisters in Islam NGO and three universities in Malaysia, it examines the perspectives of both men and women through quantitative and qualitative data analysis of over 1,200 surveys and more than 60 in-depth interviews charting the legal, financial, social, and emotional impacts of polygamy. It incorporates both progressive Islamic scholarly thought and the unique sociologically rich perspectives of the study respondents. In doing so, the data serves to strengthen advocacy for awareness and law reforms within Islamic jurisprudence frameworks and institutions. As one of the most comprehensive surveys ever conducted on polygamy in a Muslim society, this represents a major tour de force within a little explored field with tremendous potential for societal impact. This book is relevant to academics and graduate students seeking a deeper understanding of the issues related to Muslim polygamous marriage and to researchers within the broader fields of gender studies, family studies, Islamic studies, and Islamic legal studies. It is also a landmark resource for activists and policymakers seeking to advocate on behalf of marginalised groups—particularly women and children in polygamous families.