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Lipophilous carotenoids together with chlorophyll a were extracted in acetone from 1) a variety of cyanobacterial lichens stemming from habitats with strongly different light exposure, ranging from the Judean Desert, Israel, to a shaded forest floor in Germany, 2) Peltigera praetextata collected from a deciduous forest in the vicinity of Wurzburg at bimonthly intervals during an entire year, and 3) Peltigera species which in a short term experiment (five days) had been exposed to altered light conditions with respect to those they had grown under. Pigment determination by high performance liquid chromatography (HPLC) showed no clear trend in the concentrations of zeaxanthin (and echinenone) under different incident light intensities. In contrast, canthaxathin contents increased and the concentrations of chlorophyll a and beta-carotene decreased with enhanced light exposure of the lichens. This was observed for all three types of investigation and indicates that the ratio of canthaxanthin to beta-carotene in a cyano-bacterial lichen is strongly influenced by the light environment it has recently grown in.