He died of cancer

Marley received a malignant melanoma diagnosis under a toenail in July 1977. Contrary to popular belief, this lesion was not primarily brought on by an injury sustained during a football game that year but rather was a sign of an earlier cancer. Before a biopsy was performed, which proved acral lentiginous melanoma, he had to see two doctors. Contrary to other melanomas, which typically develop on sun-exposed skin, acral lentiginous melanoma develops in areas that are simple to overlook, including the soles of the feet or under toenails. Despite being the most prevalent melanoma in individuals with dark skin, it is not well-known and was not covered in the most frequently used medical textbook at the time.

Marley, citing his religious convictions, refused his physicians' advice to amputate his toe, which would have hampered his performing career. Instead, the nail and nail bed were removed, and a skin graft was taken from his thigh to cover the region. He was planning a 1980 global tour while still performing and touring despite being unwell. Malignant melanoma was found in Marley. His doctor advised amputating his toe because it was under a toenail. Marley declined nevertheless due to his religious convictions. Only his nail and nail bed were taken out. He didn't get treatment for his cancer, thus it spread and he passed away four years later.