A comprehensive sensitivity and uncertainty analysis was performed on a 1200-MW(thermal) minor actinide burner designed for a low burnup reactivity swing, negative Doppler constant, and low sodium void worth. Sensitivities of the performance parameters were generated using depletion perturbation methods for the constrained closed fuel cycle of the reactor. The uncertainty analysis was performed using the sensitivity and covariance data taken from ENDF/B-V and other published sources. The uncertainty analysis of a liquid-metal reactor for burning minor actinides has shown that uncertainties in the nuclear data of several key minor actinide isotopes can introduce large uncertainties in the predicted performance of the core. The relative uncertainties in the burnup swing, Doppler constant, and void worth were conservatively estimated to be 220, 120, and 59%, respectively. An analysis was performed to prioritize the minor actinide reactions for reducing the uncertainties.