Vulnerable groups (commercial sex workers, truck drivers, truck helpers, daily laborers, rickshaw pullers and drug users) were studied on HIV/AIDS information at Dhaka city and surrounding areas. Mass media was correlated in this research with knowledge on HIV/AIDS transmission and prevention (r = 0.22, p<0.05). Majority of respondents had radio (74%) and television (63.3%). 72.5% respondent never read newspaper and 55% never watch billboard but 31.7% watch television everyday. 95% respondents heard about the name of HIV/AIDS but none of them knew the full meaning of HIV or AIDS, and 87% knew that HIV transmits through unsafe sexual contact, 69.2% through using HIV contaminated blood and 24.2% knew that HIV transmits through contaminated syringe/needles. For sign symptom of HIV/AIDS, 25.8% considered long time cough, 23.3% long time fever, 19.2% long time diarrhoea and 15% rapid loss of body weight. Fifty percent respondents knew that using condom could prevent HIV. About 70% responded reported that they used condom during sex. Television was the main source (78.3%) of information on HIV/AIDS and mode of spread (93.3%) of HIV/AIDS was main type of information on mass media.