The present case series aims to investigate the use of polynucleotides mixed with hyaluronic acid (PNs-HA) in the form of gel to promote bone regeneration in horizontal alveolar defects. Overall, 6 adult patients underwent localized horizontal guided bone regeneration by means of xenogeneic bone substitute and a resorbable barrier with a staged approach. The graft consisted in a mixture of deproteinized bovine bone mineral (DBBM) particles and PNs-HA gel in a 3:1 ratio, respectively. The material was covered by a resorbable collagen membrane fixed with pins to the underlying bone. Implant placement was performed after 5 months. Healing proceeded uneventfully, and, upon re-entry, the graft appeared well vascularized and firmly attached to the recipient bone. Histologically, the regenerated bone appeared highly mineralized, well-organized in lamellae and totally embedding the residual granules of the biomaterial. Histomorphometric evaluations revealed that newly formed bone occupied on average 41.2% ± 12.4% of the analysed samples. Linear measurements performed on CBCT scans yielded an overall linear horizontal bone gain of 4.91 ± 0.88 mm. These data suggest that a mixture of DBBM and PNs-HA can be safely used to promote bone regeneration in case of horizontal alveolar defects.