The purpose of this study was to determine the drinking behaviors and drinking problems of adult, mentally retarded persons over 18 years old. It was also investigated whether gender, age, and pattern of employment create different result of drinking behaviors and drinking problems, and the variables explaining drinking problems were analyzed. One hundred forty adults, mentally retarded persons were surveyed in Seoul and KyeongGi area. The major findings were as follows; The majority of respondents ($58.2\%$) reported that they had consumed alcohol beverages sometimes prior to their having been interviewed. The average age of respondents who had consumed alcohol was 26.4 years and average age of first-use of alcohol was 22 years. For consumption frequency, $39.2\%$ of respondents reported that they drink alcohol once a month. Average alcohol consumption per occasion was 1.5 cups, and $10.9\%$ of respondents answered more than 5 cups per occasion. Regarding problems associated with drinking, $16\%$ of respondent of AUDIT and $51.4\%$ of Family CAGE answered that their children have drinking-related problems. Men drink more than women and experience more alcohol problems. Supervised employment group was the group with the greatest prevalence for drinking. For the amount of drinking, gender and employment pattern showed significant differences. Drinking problems (AUDIT and Family CAGE) of adult, mentally retarded persons were influenced by age of first-use of alcohol, frequency of alcohol use, and alcohol consumption.