The phototoxic effects of chlorophylls on the cells of organisms have been debated for decades. The extreme phototoxicity of uncontrolled chlorophylls and the concomitant need for rapid elimination of chlorophylls in cells have again attracted attention since the robust processes of higher plants for their catabolism during senescence have been clarified (e.g., autumnal tints). Recently, another type of chlorophyll catabolism has been identified in aquatic microbes that digest algae. Both of these processes involve the detoxification of chlorophylls: the former degrading them into colorless compounds in multiple steps and the latter rapidly converting them into colored but nonphotosensitive molecules. In this paper, we describe various ways that organisms circumvent the phototoxicity of chlorophylls, emphasizing the costs of the adaptive mechanisms against this risk to biological processes.