Single unit activity was recorded in the bed nucleus of the stria terminalis (BNST) in response to amygdaloid and hypothalamic stimulation. BNST neurons were identified by their spontaneous discharge rate, spike duration, orthodromic and antidromic responses and convergence properties. The results indicate that these neurons have characteristic electrophysiological features and that they are organized to receive amygdaloid and hypothalamic inputs with increasing convergence along a dorsal to ventral continuum.