John Jones, 50, from Rhos, Neath Port Talbot, was given 16 pints at Morriston Hospital, Swansea, after losing a leg in a forklift accident in 1990.
But one of the donors had hepatitis C, and Mr Jones died in 2012.
Recording a narrative verdict, assistant coroner Paul Bennett said infection and cirrhosis killed Mr Jones.
Dr Stephen Field, medical director of the Welsh Blood Service, offered "sincere condolences" to Mr Jones' family.
He said when Mr Jones received his transfusions there was no test available for hepatitis C. Testing was introduced throughout the UK a year after his operation.
He added: "Securing the safety of the blood supply is the number one priority of the Welsh Blood Service."
A father-of-three died more than 20 years after receiving infected blood, an inquest hears.