Caries is still considered one of the main problems of public health and many researchers in the world have been searching for alternatives to prevent the occurrence of this process. Streptococcus mutans has been isolated and identified from dental caries. The colonies of bacteria were identified by simple biochemical tests. The inhibitory effect of alcoholic plant extracts (Coffee, Cacao, Green and Black tea) on S. mutans isolated were studied by using agar well diffusion method and turbidity analysis. Coffee and Green tea showed the maximum inhibition zone against S. mutans compare with Cacao and Black tea . the result showed the MBC of Coffee, Cacao, Green and Black tea against S. mutans was 200, 500, 300 and 400 mg/ml respectively and MIC was 600, 900, 700, 900 mg/ml respectively.