Hereditary complement C3 deficiency is associated with recurrent bacterial infections and proliferative glomerulonephritis. We describe a case of an adult with complete deficiency of complement C3 due to homozygous mutations in C3 gene: c.1811delT (Val604Glyfs*2), recurrent bacterial infections, crescentic glomerulonephritis and end-stage renal failure. Following isolated kidney transplantation he would remain C3 deficient with a similar, or increased, risk of infections and glomerulonephritis. As C3 is predominantly synthesised in the liver, with a small proportion of C3 monocyte-derived and kidney-derived, he proceeded to simultaneous liver-kidney transplantation. The procedure has been successful with restoration of his circulating C3 levels, normal liver and kidney function at 26 months of follow up. Simultaneous liver-kidney transplant is a viable option to be considered in this rare setting.