In this paper, we evaluate the effect of alcohol and tobacco consumption on key species of the oral microflora. Our results show species-specific changes in two major opportunistic pathogens, such as Candida albicans and mutans streptococci, whereas other members of oral microflora are not affected by the consumption of the stimulants studied. We believe this original paper will contribute to raise awareness among the dental community towards a more personalized oral health assessment, taking in consideration alcohol and tobacco consumption in the prevention of specific oral and systemic pathologies.