<p>Health preference research plays a critical role in shaping healthcare policy and decision-making; however the underrepresentation of underserved populations challenges the validity and reliability of preference estimates. Despite efforts to diversify recruitment, health preference studies often have limited demographic diversity and non-representative sampling, leading to potentially biased findings that overlook the preferences of underserved populations. We discuss the importance of engaging underserved populations in health preference research from both ethical and research perspectives. We identify key challenges to the inclusion of underserved groups and outline strategies to address them, illustrating these with examples where possible. By prioritising inclusive and flexible methodologies, health preference researchers can generate more representative data, ensuring that estimates reflect the diverse needs and values of all populations. Ultimately, these efforts will support the development of more equitable, evidence-based, and impactful healthcare policies. </p>