In this case report, a 4 year old female terrier crossbred dog was presented with acute blindness following accidental high dose marbofloxacin administration was discussed. On initial referral to the clinic, a respiratory disease was evident, requiring antibiotic therapy and marbofloxacin (2.5 mg/kg) was prescribed. Meanwhile, patient was transferred to another veterinary practitioner specialized in large animal diseases, marbofloxacin had administered at an over dose (1050 mg/total dose through 3 days). The dog was then introduced back to our clinic with acute bilateral blindness. A diagnosis of marbofloxacin toxicity related to an overdose was made based on clinical examination and laboratory findings, excluding other relevant etiology. Dexamethasone was applied as initial treatment. In the following weeks, vision loss was eminent even without responding to bright light and not able to negotiate the obstacle course. According to the current literature, this is the first report on marbofloxacin overdose related acute blindness in dogs.