Dual diagnosis (DD) refers to the coexistence in the same individual of a substance use disorder and other mental disorder. The increase in substance use among women over the past two decades, along with related health issues and mortality rates, has underscored the importance of integrating a gender-based approach in addiction research and treatment. This transition has led to an increased focus on substance use among women and individuals of other gender identities. This narrative review aims to examine the evidence on gender differences in DD to enhance knowledge that supports the development of innovative, evidence-based policies and practices. These efforts seek to improve access to and the adequate treatment of drug use disorders and comorbid conditions among women and LGBTQIA+ individuals. Additionally, advancements in the literature on epidemiology, clinical characteristics, environmental factors, treatment needs, and final recommendations are discussed. This manuscript supports a progression from gender integration towards gender transformation – a paradigm shift extending beyond the simple incorporation of gender perspectives into existing systems towards a deeper transformation that challenges and changes current gender norms and structures, aiming for a more equitable system.