Results of studies support the suggestion that alcohol treatment after weaning produces a delay in the onset of puberty and a decrease in the weight of sex organs of male rats. The effect of alcohol on other morphologic and behavioral indices related to sexual maturation, however, has not been evaluated. In the current study, chronic consumption of alcohol (6% ethanol) in male rats, from weaning to 47 days of age, advanced the occurrence of increased values of genital grooming and spontaneous penile erections and of preputial separation, but had no effect on sex organ weight or penile spine number. Findings from the current study reflect that the effects of alcohol on the morphologic and behavioral indices of sexual maturation are distinct and emphasize the importance of studying critical peripubertal ages after chronic exposure to alcohol.