Background <p>Anti-PD-1 immunotherapy is routinely used to treat advanced melanoma cancer despite producing therapeutic benefits in less than half of patients. Given that this treatment can be associated with severe adverse effects, researchers are working to develop biomarker-based tests to predict the likely response to treatment. This study aimed to qualitatively explore patients’ views on the value of such tests and how they would affect their treatment decision-making.</p> Method <p>Semi-structured interviews were conducted with melanoma patients commencing PD-1 inhibitor therapy (<i>n</i> = 14), who were presented with a hypothetical scenario in which a blood-based biomarker prognostic test indicated the likely or unlikely success of anti-PD-1 immunotherapy.</p> Results <p>Thematic analysis identified three major themes. (1) “More knowledge is more power”: Perceived value and benefits of the test—all participants reported that such a test would be valuable, regardless of the outcome, as it would provide them with an expectation of treatment success and assist them with their treatment decision-making. (2) “It depends”: Treatment decisions shaped by test outcome—participants described how the test outcome would affect their decision to undergo PD-1 inhibitor therapy. (3) “Faith in my doctor”: Reliance on doctor’s guidance for treatment decisions—participants stated that their treating doctor’s opinion on their test outcome and subsequent advice would ultimately guide their treatment decision.</p> Conclusion <p>Melanoma patients see value in a test to predict anti-PD-1 immunotherapy response. An important consideration when communicating the outcome of this test is ensuring patients can discuss alternative treatment options and their recommendations for the best treatment option with their treating doctor.</p>