This paper describes the interrelationship among men's self-reports of symptoms, unsafe sexual behavior, and biologically tested sexually transmitted infections (STIs). Data are drawn from the baseline survey of six-year (2001-2007) research and intervention project on men's sexual health and HIV/STI risk reduction conducted in three urban poor communities in Mumbai, India. The survey collected a wide range of demographic, attitudinal, knowledge, and behavioral data. In addition, men were tested for common STIs by selecting a systematic random sub-sample of 816 men (assuming 20% non-response). Data in this paper are based on 641 men who had completed the survey interview and for whom the testing of blood and urine samples was conducted. Results suggest that the self-reported STI-like symptoms and unsafe sexual behavior taken together as a predictor of confirmed STIs improve the sensitivity to a significantly greater degree (χ² = 2.83, p<0.05) as compared to the sensitivity of self-reported STI-like symptoms or unsafe sexual behavior alone as a predictor of confirmed STIs. In addition, the consistency of self-report was found to vary among socio-demographic and behaviorally defined sub-groups. These results provide preliminary support for the importance of population-based surveys, which collect all the three types of data such as reported behavior, symptoms and laboratory confirmed STIs for a full understanding of sexual risk and STIs and for identification of sub-groups within communities that vary in their ability to identify STI symptoms.