BACKGROUND: Thaumetopoea pityocampa [pine processionary moth (PPM)] is one of the most important lepidopteran agents causing urticant cutaneous reactions in humans in Mediterranean countries. This species is also expanding northwards, because of global warming. OBJECTIVES: To investigate the prevalence, distribution by habitat group and possible risk factors of PPM cutaneous reactions in adults. METHODS: A randomly designed survey was carried out on 1224 adults. RESULTS: A point prevalence, estimated after corrections, of 8.7% was obtained (12% rural areas, 9.6% for semi-urban areas, and 4.4% for urban areas). The data showed a significantly higher risk of self-reported symptoms according to sex [p < 0.005; males, adjusted odds ratio (aOR) 1.84], habitat (p < 0.0005; rural, aOR 1.8; semi-urban, aOR 1.2), frequency of visits to pinewood areas (p < 0.005; daily exposure, aOR 2.1), and occupational exposure (p < 0.0001; aOR 5.04, 90% were males). Airborne contamination was the most important cause of reactions (83.3% of 48 participants who visited the hospital and fulfilled the criteria for a convincing reaction presented with symptoms after walking on/passing by pine tree areas). CONCLUSIONS: These findings show that PPM cutaneous reactions are common in this southern European population, including peripheral urban areas, and that the main risk is related to exposure to this insect.