Several dietary factors have been associated with the occurrence of cancers of the oral cavity and oropharynx, larynx and oesophagus, collectively called upper aerodigestive tract (UADT) cancers, but the evidence is considered as inconclusive. We hypothesised that the traditional Mediterranean dietary pattern may be more strongly inversely associated with UADT cancer risk than individual dietary components, and may explain the unexpectedly low incidence of these cancers in Greece. In the context of the European alcohol-related cancers and genetic susceptibility in Europe project, we have conducted a hospital-based case–control study in Athens, Greece, comparing 239 incident UADT cases and 194 hospital controls with admission diagnoses unrelated to tobacco, alcohol or diet. Adherence to Mediterranean diet was assessed through a widely used score, which ranges from 0 (minimal adherence) to 9 (maximal adherence) and increases with high consumption of plant foods and olive oil and low consumption of meat, dairy products and saturated lipids. Stricter adherence to the Mediterranean diet was associated with a substantial and significant decrease in UADT cancer risk (30 % for a two-unit increase in score), whereas after mutual adjustment, no individual dietary component of this diet was significantly associated with this risk. Adherence to the traditional Mediterranean diet is associated with reduced risk of UADT cancers, and may explain the lower incidence of UADT cancers in Greece, in spite of the smoking and drinking habits of this population.