In this paper, the authors present the first demonstration of a liquid-tin anode solid-oxide fuel cell (LTA-SOFC) operating on pure biodiesel (B100) prepared via base-catalyzed transesterification of virgin and waste cooking oils. The LTA-SOFC was able to convert the biodiesel to electricity at commercially viable power densities, i.e., greater than 100 mW cm(-2). The peak power for each cell was 3.5 W over an active area of 30 cm(-2), which translates to a power density of 117 mW cm(-2) and current density of 217 mA cm(-2). The peak power densities correspond to similar to 80% fuel use at the liquid-tin anode surface and overall cell efficiencies of >40%. These findings demonstrate the flexibility in operating a solid-oxide fuel cell capable of internal reforming from a blend of petroleum- and biomass-derived diesels for greater resource flexibility. Cells were operated for short times (similar to 4.5 h), owing to the experimental nature of the balance of plant. Results support future efforts in developing an efficient balance-of-plant system for demonstrating long-term (>1000 h) power generation from biodiesel using the LTA-SOFC design.