Objective The aim of this study was to examine the effect of short-term low-frequency electrical stimulation (SLES) on nerve regeneration of 8-week delayed peripheral nerve injury with a long gap. Methods Left sciatic nerves of adult female Sprague Dawley rats were transected. Next, 8-week-delayed defective nerve models were prepared followed by trimming of the nerve stumps. SLES was applied to the experimental group after the nerve defects had been bridged by contralateral normal sciatic nerves. The nerve defects were also bridged without SLES in the control group. After the animals had been fed for different times as required, tissue specimens were harvested to examine expression of endogenous neurotrophic factors and morphological behavior of regenerating nerves through histological techniques such as Meyer’s trichrome staining, immunofluorescent double-staining, retrograde tracing, and electron microscopy. Results Expression levels of endogenous neurotrophins were higher and more rapidly observed following electrical stimulation. No improved performance of nerve regeneration was found in either development of nerve fibers or reinnervation of target organs. Conclusions The ability of SLES to promote nerve regeneration after a long delay (more than 8 weeks) was limited.