Background: Most cutaneous malignant melanomas of the skin are visible and should, at least in theory, be possible to detect with the naked eye. Objective: This study was conducted to learn more about laypersons' ability to discriminate between benign pigmented lesions and malignant ones. Methods: Four groups of laypersons (n = 120) were asked to evaluate pictures of different types of pigmented skin lesions, before and after they received information about the ABCD (asymmetry, border irregularity, color variegation, and diameter greater than 6 mm) criteria, with respect to the necessity of action. Results: The respondents made adequate assessments of melanomas but overestimated the danger of benign pigmented skin lesions. Information about the ABCD criteria enhanced their ability to make adequate assessments. Conclusion: People seem to make adequate decisions concerning how to act if they have a melanoma. On the other hand, common moles and dysplastic nevi were harder to discriminate. Providing information to the public about the features of melanomas, in accordance with the ABCD criteria, might help laypersons in their perceptual discrimination of skin lesions. (J Am Acad Dermatol 2002;46;667-73.)