Colonoscopy, as a frequently performed diagnostic and therapeutic procedure, is fairly safe to patients with colorectal disorders generally. Incarceration of a colonoscope refers to the colonoscope is unable to be advanced or withdrawn due to some causes e.g. inguinal hernia, which is an unusual complication during colonoscope procedure. We present a case report of incarceration of the colonoscope in a left inguinal hernia. This case report reiterates the importance of this rare complication of colonoscopy and discusses its etiology and treatment. Clinicians and colonoscopists should be cautious of this possible complication to prevent unfavorable outcomes.