AbstractTonoplast preparations were obtained from leaves ofHordeum vulgare(C3),Kalanchoë daigremontiana(obligate CAM) andMesembryanthemum crystallinum(C3and inducible CAM). Lipid analyses showed reproducible patterns comprising free sterols, glycolipids of plastidic origin, glucose‐containing lipids (steryl glucoside, acylated steryl glucoside, cerebroside) and phospholipids. Predominant components were sterols, cerebrosides, phosphatidyl choline and phosphatidyl ethanolamine. Very long chain fatty acids were found in phosphatidyl serine and hydroxy fatty acids in cerebrosides. Isolation of tonoplasts via protoplasts and vacuoles may have resulted in reduced levels of free sterols. The data show a similarity between tonoplasts and plasma membranes with respect to lipid profiles. Lipid composition was neither affected by different CO2‐fixation mechanisms nor by salt‐induced changes inMesembryanthemum crysta