Phoenixin-14 (PNX) - a bioactive peptide recently discovered in the rat brain, is highly conserved among many animal species: rodents (rat, mouse), pig, dog as well as humans. In rodents, PNX is expressed in areas responsible for the transmission of sensory information dorsal root ganglia (DRG) neurons, where it is present at relatively high levels and may preferentially suppress visceral pain. However, so far the presence of PNX has not been investigated in DRG in pigs, a species which, due to its anatomical and histological similarity to humans, is considered a better model for biomedical studies than rodents. The present study aimed to investigate the immunoreactivity of PNX in the DRG of the domestic pig. The collected spinal ganglia from the cervical (C), thoracic (Th), lumbar (L) and sacral (S) sections were transversely divided into serial sections of 10 μm thickness. DRG sections from each level of the spinal cord were double-labeled immunohistochemically using antibodies to PNX in a mixture with antibodies to: cocaine and amphetamine related transcript (CART), calretinin (CRT), calcytonin gene-related peptide (CGRP), galanin (GAL), nitric oxide synthase (nNOS), pituitary adenylate cyclase-acrivating polypeptide (PACAP), substance P (SP) or somatostatin (SOM), respectively. Immunohistochemical studies revealed PNX immunoreactivity in approximately 20% of nerve cells in all DRG examined, highlighting mainly the presence of the peptide in cells of small diameter (approximately 74% of all PNX-positive neurons found). Double labeling of DRG sections showed that PNX-immunopositive neurons stained also for CGRP (96.1%), SP (88.5%), nNOS (52.1%), GAL (20.7%), CRT (10.05%), PACAP (7.4%), CART (5.1%), or SOM (4.7%). Our research revealed for the first time the presence of the new peptide PNX in the sensory ganglia of the domestic pig, its co-localization with other important neurotransmitters involved in sensory transmission and its percentage distribution in ganglion domains. The exact function of PNX in DRG is not yet known, however, the high degree of co-localization of this peptide with the main nociceptive transmitters SP and CGRP may indicate its function in modulation of pain transmission.