Objectives: This study will assess the relationship between vitamin D concentration at melanoma diagnosis and melanoma tumor characteristics, in individuals in a high ultraviolet radiation (UVR) environment. Methods: We aim to recruit 600 recently diagnosed melanoma patients from Queensland, Australia, a high UVR location with one of the world’s highest melanoma incidence rates. Patients are recruited through general practitioner, skin cancer specialist, dermatological and hospital-based practices. As close as possible to diagnosis, participants provide a blood sample for vitamin D analysis and have their sun exposure/sun protection behavior, melanoma risk factors and dietary vitamin D intake assessed by questionnaire and phone interview. Details of tumor pathology, including tumor level, thickness, and ulceration, are abstracted from cancer registry records. Here, we describe the study methods and present preliminary findings from early participants. Results: As of December 2017, we have recruited 128 participants (48% male, mean age 60.2 years, mean Breslow thickness 0.63 mm). Conclusions: When complete, this study will give insights into the association between vitamin D at diagnosis and melanoma tumor characteristics whilst adjusting for recent sun exposure and sun protection use. This study may impact military sun exposure and nutrition policies as vitamin D may play a role in melanomagenesis.