The neuronal survival promoting ability of brain derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF), individually and in combination, was evaluated in dissociated cell cultures of postnatal day 5 (P5) rat acoustic ganglia. The neuritogenic promoting effect of these same neurotrophic factors was examined in organotypic explants of P5 rat acoustic ganglia. The results showed that BDNF was maximally effective at a concentration of 10 ng/mL in promoting both survival and neuritogenesis of these postnatal auditory neurons in vitro. CNTF was maximally effective at a concentration of 0.01 ng/mL at promoting both survival and neuritogenesis in the acoustic ganglion cultures. BDNF had its strongest effect on neuronal survival while CNTF was most effective in stimulating neurite outgrowth. These two neurotrophic factors, when added together at their respective maximally effective concentrations, behave in an additive manner for promoting both survival and neuritic outgrowth by the auditory neurons. © 1996 John Wiley & Sons, Inc.