The erosion caused in vitro by cola-type and guaraná-type beverages (the latter is a soft drink sold in Brazil), and a canned lemon juice on the enamel of human deciduous teeth was analyzed. Morphological analysis of affected enamel was done using stereomicroscopy and scanning electron microscopy (SEM). The harmful effect of all test products on deciduous enamel was clearly demonstrated. Stereomicroscopy showed loss of gloss and an alteration in normal color of enamel, with irregular loss of dental tissue in variable degrees. Such a loss became more serious as the time of incubation increased. Different degrees of solubilization of enamel prisms were demonstrated by SEM, affecting initially the sheaths and the heads of prisms and later their tails. Areas of erosion increased in proportion to the time of incubation. All the products showed a great erosive potential on human deciduous dental enamel.