Developmental defects of dental enamel are very common with at least one in every three individuals having one or more teeth with obvious non-carious defect. The more common defects are opaque areas, hypoplasias (missing enamel) and discoloured enamel; the variety in form, severity and combination of defects is extensive. The lesions are sequelae of systemic, traumatic or genetic events during tooth development. A review of past and current terminologies, and classifications of developmental defects of enamel, reveals ambiguities, deficiencies and lack of uniformity in methods and criteria used in their study. The principal objective for collecting and recording observations on enamel defects is to determine their frequency, severity and distribution for the purpose of assessing the magnitude of the clinical problem they generate and their aetiology. Hence, an internationally recognized classification of developmental enamel defects and recording procedure would increase the value and comparability of future studies. An acceptable uniform terminology and a simple procedure for classifying the more commonly observed defects, defined by their visual characteristics, would achieve these aims. A classification is proposed which identifies and defines the type, number and location of developmental defects affecting tooth enamel on the buccal and lingual surfaces of all teeth. The procedure has been designed for easy interpretation and simple evaluation. It may be modified for use with much less extensive clinical examination.