Polygyny is a matrimonial union in which a single man is simultaneously married to multiple wives. On a daily basis, women in polygynous unions suffer from financial, emotional and physical burdens. This study explores women’s perceptions of this matrimonial regime and the factors influencing their sexual health decision-making in Cameroon. Drawing on interviews with twenty-three women aged 23 to 80 years living in polygynous unions, we explore women’s daily life and perceptions on polygyny. Using content analysis, meaning units relating to respondents’ experiences and perceptions were identified and condensed into codes and categories that were later grouped into themes. Five themes emerged – refusal and tolerance; heavy workload and responsibility; lack of power in sexual health decision-making; discrimination and unequal treatment of spouses; and emotional suppression. Women reported emotional suppression, limited rights, discrimination and poor living conditions as being the most significant problems that they encountered. Addressing the discrimination faced by women in polygynous unions will entail adopting and implementing laws to protect women’s rights and promote their empowerment.