Celiac disease (CD) is one of the most common immune-mediated diseases with a worldwide prevalence of around 1%, although a couple of decades ago the disease was thought to be very rare. CD is characterized by an inadequate inflammatory response to gluten in genetically susceptible individuals. In this inflammatory response both the adaptive and innate immunity are involved. The clinical picture of CD is variable ranging from severe malabsorption syndrome to silent cases. Disease specific antibodies can aid in selecting patients for a small intestinal biopsy, which is thought to be the gold standard investigation to diagnose CD. However, in selected patients, serology can be sufficient to confirm the diagnosis and a biopsy is not needed. Hitherto, the only treatment for CD is adherence to a lifelong strict gluten-free diet. The purpose of this review was to summarize current literature on the epidemiology and pathophysiology of CD and to discuss diagnostic and therapeutic approaches.