Currently, there has been little research from a Health Economics as well as a Public Health perspective, which looks at the Economics of HIV and AIDS, and Risky Sexual Behaviour of Young Females in relation to poverty. Consequently a hot debate has resulted. This book uses dataset from the first wave of a study on young female adult (YAFAs) done in Balaka district in Malawi, by the University of Pennsylvania under the Tsogolo La Thanzi (TLT) project. The sample size was 1493.The decision to indulge in risky sexual behaviour is modeled as a choice model and estimated using a probit model. Among other things, the study shows that income, wealth status, HIV and AIDS knowledge, are insignificant in determining risky sexual behaviour. However, perception on condom uses, education, and employment status are found to be predictors of risky sexual behaviour. The conclusions drawn so far have far reaching implications for Health Economist and Public Health specialists as the results seem to be diverting away from the conventional beliefs, given the Malawian scenario.