Epileptic seizures in Alzheimer’s disease (AD) patients are rare but still approximately 8 times more common than in the general age-matched population. Experimental and clinical studies have suggested the epileptogenic potential of Aβ, which might represent a principal responsible for the epileptic-like discharges and cognitive decline observed in AD. In addition, an increase in cortical excitability has been demonstrated in AD animal models that may be due to an imbalance of excitatory/inhibitory synaptic transmission. Cortical hyperexcitability has also been demonstrated in the human EEG by the presence of a high proportion of fast oscillatory activities. This review tries to show the mechanisms involved in the generation of the epileptic seizures observed in AD and have been widely studied in animal models. Unfortunately, the EEG analysis in AD is not a standard procedure in clinical practice. Nevertheless, seizures and other electroencephalographic abnormalities are commonly found in AD patients. We suggest that EEG studies in these patients could help to an early diagnosis and inform about the evolution of this disease and their possible cognitive deterioration.