Some humans are often exposed to airborne mineral dusts at the workplace or in daily life. When inhaled, some kinds of mineral dusts can trigger a pathological response of the respiratory system. Silicosis (from silica dust) and asbestosis (from asbestos fibres) are the most commonly known diseases originating from inhaled mineral dusts; other examples are bronchogenic carcinoma and mesothelioma. Detailed knowledge of the chemical (and physical) factors underlying mineral dust toxicity is much needed in order to evaluate the relative risks from exposure to different kinds of materials, both natural and synthetic. These pathogenic factors have been reviewed, with a focus on the surface chemistry of mineral particles and interface phenomena. To facilitate understanding, an outline of the anatomy of the respiratory system and of the etiology of the main diseases involved is also given.