Objective: Our previous study demonstrated the presence of environmental tremolite and chrysotile asbestos fiber exposure in Hekimhan town in Malatya located in eastern Turkey. The aim of this study was to investigate whether environmental asbestos exposure increases the incidence of lung cancer and mesothelioma. Method: One hundred and forty-nine patients with mesothelioma and lung cancer living in the center or in the towns of Malatya were retrospectively analyzed. The Incidences of lung cancer and mesothelioma were calculated. Results: The incidences of lung cancer and mesothelioma were 3.39/100,000 and 0.21/100,000, respectively, for the whole population of Malatya; while they were 8.23/100,000 and 1.45/100,000 in Hekimhan. The incidences were strikingly high (22.39/100,000 for lung cancer and 7.46/100,000 for mesothelioma) in Arguvan, another town in Malatya where an analysis for asbestos could not be performed. The overall incidence in Turkey was reported as 5.9/100,000 by the Health Ministry in 1994. The incidences of lung cancer were nearly 1.3-fold higher in Hekimhan and fourfold higher in Arguvan then in the general population of Turkey. Conclusion: The incidences of mesothelioma and lung carcinoma in Hekimhan were higher than those of the general population in Turkey, suggesting a role of environmental asbestos exposure in lung cancer and mesothelioma.