Socioeconomic inequalities cause different tobacco consumption patterns. The purpose of this study was to examine the relationship between educational level and smoking behaviour, including type of tobacco consumption, in lung cancer patients. To this end, epidemiological analyses of 801 lung cancer patients recruited for a case-control study in four public hospitals in Asturias, Spain, between October 2000 and April 2006 were carried out. Smoking behaviour and educational level data were obtained through personal interview. Analyses indicated that the probability of heavy smoking among low educational-level patients was approximately twice as high as for high educational-level patients (RRR>31.2 packs/years=2.04; CI 95%=1.15-3.62; RRR>52packs/years=2.14; CI 95%=0.98-4.64). Low-educated patients were more than three times as likely to be long-time smokers (RRR>40 years=3.30; CI 95%=1.43-7.62). The probability of smoking exclusively black tobacco was almost four times greater in low educational-level patients (RRRblack only=3.72; CI 95%=1.23-11.19). The results show that there are broad educational inequalities with regard to the quantity, duration and type of tobacco consumption among lung cancer patients in Northern Spain.