The number of subjects in studies on human spatial hearing is generally small. Therefore, individual differences and the factors underlying variability are unknown. In this study, we investigated across-listener variability in auditory localization abilities in a group of 50 naïve adults with normal hearing. Targets were trains of low-frequency noise bursts presented to 1 of 12 hidden speakers in the azimuthal plane. We observed less across-listener variability in the variance of individual responses but more in the root-mean-square and signed errors, which tended to increase with target angle. One third of the listeners demonstrated systematically smaller signed errors with left-sided targets than with right-sided ones. These asymmetries were observed less frequently in left-handers and females than in right-handers and males. Performance was not correlated with age. About 4 of 6 listeners trained with sensory feedback showed no reduction of asymmetries with training but rather showed a reduction in errors on their "best" side. Across-listener variability in the asymmetry of brain organization, notably linked to handedness or gender, is discussed.