Creutzfeldt-Jakob disease (CJD) is a prion disease manifesting with signs of impaired conscious and mental state, cerebellar ataxia, myoclonus, and loss of vision. Since the disease progresses rapidly to death, it is important to distinguish it from other diseases. The exact diagnosis is made by postmortem histopathological analysis of the brain. The diagnosis of CJD is difficult because the clinical presentation varies between cases. In this paper, we present two cases of CJD. The first case was a 50-year-old male who was admitted with agitation, impaired consciousness and involuntary movements for three months. The second case was a 70-year-old male presented with forgetfulness, total loss of vision in the form of conversion disorder and ataxia. Diagnostic support was provided by magnetic resonance imaging (MRI) and electroencephalography (EEG). Increased cerebrospinal fluid concentration of 14.3.3 protein was determined. As a result, prion disease was considered in these cases due to rapid progression of the neuropsychiatric symptoms. Repeated EEG and MRI are useful for diagnosis in these patients. Although there is not effective treatment, diagnosis of the condition is very important in terms of preventive measures.