Free sex has become a serious problem in Indonesia. This problem as a result of lack of knowledge and understanding of sexuality issues, wrong determination about love as well as least knowledge of the impact that occurs because of deviant sexual behavior such as : sexually transmitted diseases (STDs), urinary tract infection (UTI), HIV-AIDS and also various types of other diseases. Research on the relationship between the level of knowledge, attitudes and sexual behavior needs to be done to examine this problem. This study uses analytic design with cross sectional approach. The population used was workers of PT Esa Express Surabaya held an active sexual behavior. The amount of sample are 44 respondents and taken by total sampling. In the statistical calculation of Pearson correlation test between variables found three results. The relation between knowledge and behavior variables is positive (direct) and significant correlation with the probability (0,00)<0.05. Judging from the magnitude of the correlation coefficient, variable relations knowledge and behavior is strong (0.848). While the relation of variables were also positive on attitudes and behavior (direct) and significant by Pearson correlation probability (0,00)<0.05. Judging from the magnitude of the correlation coefficient, the relationship variables attitude and behavior was low (0.327). While the variable relation of knowledge and attitudes are also positive (direct) and significant correlation with the probability (0,00)<0.05. Judging from the magnitude of the correlation coefficient, the relation between variables of knowledge and attitude is in moderate level (0.422). From the results of this study concluded that there is a positive relation (direct) between the level of knowledge, attitudes and sexual behavior in a population of workers in PT Esa Express Surabaya. In the better level of knowledge, the better behavior and attitude will toward and impact on sexual behavior