This study evaluated the impact of hyaluronic acid gel (HA) and bone marrow (BM) on healing of tenotomized Achilles tendon in dogs. Under general anesthesia, eighteen adult local dogs were enrolled randomly into three equal groups (6 dogs each). All animals were subjected the same condition of accommodation. Right hind limb at Achilles tendon was prepared aseptically. A linear incision (3-5 cm in length) was carried out over the skin directly at the site of proximal part of Achilles tendon, then the tendon resected transversely. The ends of resected tendon were sewed with 3/0 nylon suture material. The dogs were divided into 3 equal groups according to treatment; first group as control, second group (treated with HA) and third group (treated with BM). Clinical, ultrasonographical and hitopathological assessments were done during (15,30, 60 days). Clinically, there was no signs of inflammatory reaction or severe lameness along the period of treatment. Ultrasonographic investigations results in HA and BM groups at 60 days indicated normal echotexture pattern of the tendon with superior changes in BM group in which the tendon returned to the normal feature. Histopathological results at 60 days in BM group showed highly vasculature and mature collagen fibers. Immunohistochemical results of IL-6 at 15 days in BM group indicated intense positive expression in this group superior than the other groups. In conclusion the impact of BM on healing progressing of tenotomized Achilles tendon in dogs is superior to the impact of HA regarding the clinical, ultrasonography, histopathology and immunohistochemistry findings.