The use of Lucilia sericata larvae on the healing of wounds in diabetics has been reported. However, the role of the excretion/secretion (ES) products of the larvae in treatment of diabetic wounds remains unknown. This study investigated whether application of the ES products of L. sericata on the wound surface could improve the impaired wound healing in streptozotocin-induced diabetic rats. Additional analysis was performed to understand proteome content of L. sericata secretome to understand ES contribution at the molecular level. For this purpose, full-thickness skin wounds were created on the backs of diabetic and control rats. A study was conducted to assess the levels of the ES-induced collagen I/III expression and to assay nuclear factor B (NF-B) (p65) activity in wound biopsies and ES-treated wounds of diabetic rat skin in comparison to the controls. The expression levels of collagen I/III and NF-B (p65) activity were determined at days 3, 7, and 14 after wounding using immunohistological analyses and enzyme-linked immunosorbent assay technique. The results indicated that treatment with the ES extract increased collagen I expressions of the wound control and diabetic tissue. But the increase in collagen I expression in the controls was higher than the one in the diabetics. NF-B (p65) activity was also increased in diabetic wounds compared to the controls, whereas it was decreased in third and seventh days upon ES treatment. The results indicated that ES products of L. sericata may enhance the process of wound healing by influencing phases such as inflammation, NF-B (p65) activity, collagen synthesis, and wound contraction. These findings may provide new insights into understanding of therapeutic potential of ES in wound healing in diabetics.