Electrophysiological recordings in the olfactory nerve of the European pike Esox lucius were done as early as at the beginning of the 20th century, but since then, the nerve has not been extensively studied. It contains 4 to 6 millions unmyelinated sensory axons, with a relatively homogenous population of sizes, more than 95% have diameters of about 0.2 µm. The aim of our work concerned the keeping conditions under which reproducible electrophysiological responses can be obtained, and some of the electrophysiological properties of these unmyelinated sensory axons. Particular attention has been given to the dissection of the pike olfactory nerve. We have adapted the technique described by von Muralt et al. (1976) to obtain the nerves more quickly and to prolong their survival. For the latter aim, we have found that a medium, used to keep excised Xenopus oocytes for many days, kept 69% of the nerves functional for up to 3 days. The diphasic compound action potential (CAP) of the pike olfactory nerve propagated at a velocity of 12 ± 0.5 cm/s (n = 37) and was suppressed by tetrodotoxin (10 µM), known to block voltage-activated sodium channels. Nerve CAP kinetics were noticeably modified when tested after about 3 h in the medium at room temperature. However, the nerves produced consistent CAP during 30-60 min in the recording chamber in air. While preliminary, our results indicate that the olfactory nerve of the European pike, Esox lucius, by its survivability may be a suitable model for electrophysiological and pharmacological studies of unmyelinated sensory axons.