Acquired Immune Deficiency Syndrome (AIDS) remains a public health problem of major significance in most parts of the world. The first HIV infection was detected in 1988 in Nepal. Since then HIV and AIDS epidemic has evolved from low to concentrated among “High risk groups” i.e. Injecting Drug Users (IDUs), Female Sex Workers (FSWs), Men having Sex with Men (MSM) and Seasonal labor Migrants. The objective of this study was to find out knowledge, attitude on HIV-AIDS among the respondents and assess the types of behavior that places them at risk of contracting HIV_AIDS in Jhapa district of Nepal. This was the cross sectional descriptive study carried out among High risk behavior group (FSWs, and Clients of FSWs) who come for treatment at VCT centre of Jhapa district. Multi stage purposive and random sampling was adopted and data were collected using a pre-tested interview schedule. Maximum no. of respondents (98.9 %) had heard about HIV and (100.0 %) had heard about AIDS, (100.0 %) using condom, among which (82.2%) used consistently. About half of the respondents (50.1%) had thought that they have chances of contracting HIV/AIDS. Sex at an early age was the prevalent practice among the study population as (46 .6 %) of them reported to have initiated before the age of 15 years. As the age at first sex increases RTI problems decreases (p=0.018) and vice versa. Less than half of the respondents (71.2%) had used alcohol during sexual activity, among which, (59.6%) had neglected to use condom. Knowledge about HIV-AIDS and condom was high. More than half of the respondent perceived their high risk to HIV/AIDS infection, judging from their present sexual behavior. The frequency of condom use was unsatisfactory (82.2%). Alcohol use and negligence to use condom during sexual activity was high.